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2016-07-03KVM: arm/arm64: The GIC is dead, long live the GICMarc Zyngier
I don't think any single piece of the KVM/ARM code ever generated as much hatred as the GIC emulation. It was written by someone who had zero experience in modeling hardware (me), was riddled with design flaws, should have been scrapped and rewritten from scratch long before having a remote chance of reaching mainline, and yet we supported it for a good three years. No need to mention the names of those who suffered, the git log is singing their praises. Thankfully, we now have a much more maintainable implementation, and we can safely put the grumpy old GIC to rest. Fellow hackers, please raise your glass in memory of the GIC: The GIC is dead, long live the GIC! Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-20KVM: arm/arm64: Fix MMIO emulation data handlingChristoffer Dall
When the kernel was handling a guest MMIO read access internally, we need to copy the emulation result into the run->mmio structure in order for the kvm_handle_mmio_return() function to pick it up and inject the result back into the guest. Currently the only user of kvm_io_bus for ARM is the VGIC, which did this copying itself, so this was not causing issues so far. But with the upcoming new vgic implementation we need this done properly. Update the kvm_handle_mmio_return description and cleanup the code to only perform a single copying when needed. Code and commit message inspired by Andre Przywara. Reported-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com>
2016-05-20KVM: arm/arm64: Get rid of vgic_cpu->nr_lrChristoffer Dall
The number of list registers is a property of the underlying system, not of emulated VGIC CPU interface. As we are about to move this variable to global state in the new vgic for clarity, move it from the legacy implementation as well to make the merge of the new code easier. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com>
2016-05-20KVM: arm/arm64: vgic: Remove irq_phys_map from interfaceAndre Przywara
Now that the virtual arch timer does not care about the irq_phys_map anymore, let's rework kvm_vgic_map_phys_irq() to return an error value instead. Any reference to that mapping can later be done by passing the correct combination of VCPU and virtual IRQ number. This makes the irq_phys_map handling completely private to the VGIC code. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-20KVM: arm/arm64: Remove the IRQ field from struct irq_phys_mapChristoffer Dall
The communication of a Linux IRQ number from outside the VGIC to the vgic was a leftover from the day when the vgic code cared about how a particular device injects virtual interrupts mapped to a physical interrupt. We can safely remove this notion, leaving all physical IRQ handling to be done in the device driver (the arch timer in this case), which makes room for a saner API for the new VGIC. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@linaro.org>
2016-05-20KVM: arm/arm64: vgic: avoid map in kvm_vgic_unmap_phys_irq()Andre Przywara
kvm_vgic_unmap_phys_irq() only needs the virtual IRQ number, so let's just pass that between the arch timer and the VGIC to get rid of the irq_phys_map pointer. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-20KVM: arm/arm64: vgic: avoid map in kvm_vgic_map_is_active()Andre Przywara
For getting the active state of a mapped IRQ, we actually only need the virtual IRQ number, not the pointer to the mapping entry. Pass the virtual IRQ number from the arch timer to the VGIC directly. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-20KVM: arm/arm64: vgic: avoid map in kvm_vgic_inject_mapped_irq()Andre Przywara
When we want to inject a hardware mapped IRQ into a guest, we actually only need the virtual IRQ number from the irq_phys_map. So let's pass this number directly from the arch timer to the VGIC to avoid using the map as a parameter. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-20KVM: arm/arm64: vgic: streamline vgic_update_irq_pending() interfaceAndre Przywara
We actually don't use the irq_phys_map parameter in vgic_update_irq_pending(), so let's just remove it. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-03KVM: arm/arm64: vgic: Rely on the GIC driver to parse the firmware tablesJulien Grall
Currently, the firmware tables are parsed 2 times: once in the GIC drivers, the other time when initializing the vGIC. It means code duplication and make more tedious to add the support for another firmware table (like ACPI). Use the recently introduced helper gic_get_kvm_info() to get information about the virtual GIC. With this change, the virtual GIC becomes agnostic to the firmware table and KVM will be able to initialize the vGIC on ACPI. Signed-off-by: Julien Grall <julien.grall@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-02-23KVM: arm/arm64: vgic: Ensure bitmaps are long enoughMark Rutland
When we allocate bitmaps in vgic_vcpu_init_maps, we divide the number of bits we need by 8 to figure out how many bytes to allocate. However, bitmap elements are always accessed as unsigned longs, and if we didn't happen to allocate a size such that size % sizeof(unsigned long) == 0, bitmap accesses may go past the end of the allocation. When using KASAN (which does byte-granular access checks), this results in a continuous stream of BUGs whenever these bitmaps are accessed: ============================================================================= BUG kmalloc-128 (Tainted: G B ): kasan: bad access detected ----------------------------------------------------------------------------- INFO: Allocated in vgic_init.part.25+0x55c/0x990 age=7493 cpu=3 pid=1730 INFO: Slab 0xffffffbde6d5da40 objects=16 used=15 fp=0xffffffc935769700 flags=0x4000000000000080 INFO: Object 0xffffffc935769500 @offset=1280 fp=0x (null) Bytes b4 ffffffc9357694f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769510: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769520: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769530: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769540: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769550: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769560: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769570: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Padding ffffffc9357695b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Padding ffffffc9357695c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Padding ffffffc9357695d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Padding ffffffc9357695e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Padding ffffffc9357695f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ CPU: 3 PID: 1740 Comm: kvm-vcpu-0 Tainted: G B 4.4.0+ #17 Hardware name: ARM Juno development board (r1) (DT) Call trace: [<ffffffc00008e770>] dump_backtrace+0x0/0x280 [<ffffffc00008ea04>] show_stack+0x14/0x20 [<ffffffc000726360>] dump_stack+0x100/0x188 [<ffffffc00030d324>] print_trailer+0xfc/0x168 [<ffffffc000312294>] object_err+0x3c/0x50 [<ffffffc0003140fc>] kasan_report_error+0x244/0x558 [<ffffffc000314548>] __asan_report_load8_noabort+0x48/0x50 [<ffffffc000745688>] __bitmap_or+0xc0/0xc8 [<ffffffc0000d9e44>] kvm_vgic_flush_hwstate+0x1bc/0x650 [<ffffffc0000c514c>] kvm_arch_vcpu_ioctl_run+0x2ec/0xa60 [<ffffffc0000b9a6c>] kvm_vcpu_ioctl+0x474/0xa68 [<ffffffc00036b7b0>] do_vfs_ioctl+0x5b8/0xcb0 [<ffffffc00036bf34>] SyS_ioctl+0x8c/0xa0 [<ffffffc000086cb0>] el0_svc_naked+0x24/0x28 Memory state around the buggy address: ffffffc935769400: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffffffc935769480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffffffc935769500: 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffffffc935769580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffffffc935769600: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Fix the issue by always allocating a multiple of sizeof(unsigned long), as we do elsewhere in the vgic code. Fixes: c1bfb577a ("arm/arm64: KVM: vgic: switch to dynamic allocation") Cc: stable@vger.kernel.org Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-12Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "PPC changes will come next week. - s390: Support for runtime instrumentation within guests, support of 248 VCPUs. - ARM: rewrite of the arm64 world switch in C, support for 16-bit VM identifiers. Performance counter virtualization missed the boat. - x86: Support for more Hyper-V features (synthetic interrupt controller), MMU cleanups" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (115 commits) kvm: x86: Fix vmwrite to SECONDARY_VM_EXEC_CONTROL kvm/x86: Hyper-V SynIC timers tracepoints kvm/x86: Hyper-V SynIC tracepoints kvm/x86: Update SynIC timers on guest entry only kvm/x86: Skip SynIC vector check for QEMU side kvm/x86: Hyper-V fix SynIC timer disabling condition kvm/x86: Reorg stimer_expiration() to better control timer restart kvm/x86: Hyper-V unify stimer_start() and stimer_restart() kvm/x86: Drop stimer_stop() function kvm/x86: Hyper-V timers fix incorrect logical operation KVM: move architecture-dependent requests to arch/ KVM: renumber vcpu->request bits KVM: document which architecture uses each request bit KVM: Remove unused KVM_REQ_KICK to save a bit in vcpu->requests kvm: x86: Check kvm_write_guest return value in kvm_write_wall_clock KVM: s390: implement the RI support of guest kvm/s390: drop unpaired smp_mb kvm: x86: fix comment about {mmu,nested_mmu}.gva_to_gpa KVM: x86: MMU: Use clear_page() instead of init_shadow_page_table() arm/arm64: KVM: Detect vGIC presence at runtime ...
2015-12-14KVM: arm/arm64: vgic: make vgic_io_ops staticJisheng Zhang
vgic_io_ops is only referenced within vgic.c, so it can be declared static. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-11KVM: arm/arm64: vgic: Fix kvm_vgic_map_is_active's dist checkChristoffer Dall
External inputs to the vgic from time to time need to poke into the state of a virtual interrupt, the prime example is the architected timer code. Since the IRQ's active state can be represented in two places; the LR or the distributor, we first loop over the LRs but if not active in the LRs we just return if *any* IRQ is active on the VCPU in question. This is of course bogus, as we should check if the specific IRQ in quesiton is active on the distributor instead. Reported-by: Eric Auger <eric.auger@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-11-24KVM: arm/arm64: vgic: Trust the LR state for HW IRQsChristoffer Dall
We were probing the physial distributor state for the active state of a HW virtual IRQ, because we had seen evidence that the LR state was not cleared when the guest deactivated a virtual interrupted. However, this issue turned out to be a software bug in the GIC, which was solved by: 84aab5e68c2a5e1e18d81ae8308c3ce25d501b29 (KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.active, 2015-11-24) Therefore, get rid of the complexities and just look at the LR. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.activeChristoffer Dall
We were incorrectly removing the active state from the physical distributor on the timer interrupt when the timer output level was deasserted. We shouldn't be doing this without considering the virtual interrupt's active state, because the architecture requires that when an LR has the HW bit set and the pending or active bits set, then the physical interrupt must also have the corresponding bits set. This addresses an issue where we have been observing an inconsistency between the LR state and the physical distributor state where the LR state was active and the physical distributor was not active, which shouldn't happen. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-05Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "First batch of KVM changes for 4.4. s390: A bunch of fixes and optimizations for interrupt and time handling. PPC: Mostly bug fixes. ARM: No big features, but many small fixes and prerequisites including: - a number of fixes for the arch-timer - introducing proper level-triggered semantics for the arch-timers - a series of patches to synchronously halt a guest (prerequisite for IRQ forwarding) - some tracepoint improvements - a tweak for the EL2 panic handlers - some more VGIC cleanups getting rid of redundant state x86: Quite a few changes: - support for VT-d posted interrupts (i.e. PCI devices can inject interrupts directly into vCPUs). This introduces a new component (in virt/lib/) that connects VFIO and KVM together. The same infrastructure will be used for ARM interrupt forwarding as well. - more Hyper-V features, though the main one Hyper-V synthetic interrupt controller will have to wait for 4.5. These will let KVM expose Hyper-V devices. - nested virtualization now supports VPID (same as PCID but for vCPUs) which makes it quite a bit faster - for future hardware that supports NVDIMM, there is support for clflushopt, clwb, pcommit - support for "split irqchip", i.e. LAPIC in kernel + IOAPIC/PIC/PIT in userspace, which reduces the attack surface of the hypervisor - obligatory smattering of SMM fixes - on the guest side, stable scheduler clock support was rewritten to not require help from the hypervisor" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (123 commits) KVM: VMX: Fix commit which broke PML KVM: x86: obey KVM_X86_QUIRK_CD_NW_CLEARED in kvm_set_cr0() KVM: x86: allow RSM from 64-bit mode KVM: VMX: fix SMEP and SMAP without EPT KVM: x86: move kvm_set_irq_inatomic to legacy device assignment KVM: device assignment: remove pointless #ifdefs KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomic KVM: x86: zero apic_arb_prio on reset drivers/hv: share Hyper-V SynIC constants with userspace KVM: x86: handle SMBASE as physical address in RSM KVM: x86: add read_phys to x86_emulate_ops KVM: x86: removing unused variable KVM: don't pointlessly leave KVM_COMPAT=y in non-KVM configs KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr() KVM: arm/arm64: Clean up vgic_retire_lr() and surroundings KVM: arm/arm64: Optimize away redundant LR tracking KVM: s390: use simple switch statement as multiplexer KVM: s390: drop useless newline in debugging data KVM: s390: SCA must not cross page boundaries KVM: arm: Do not indent the arguments of DECLARE_BITMAP ...
2015-11-04KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr()Pavel Fedin
Now we see that vgic_set_lr() and vgic_sync_lr_elrsr() are always used together. Merge them into one function, saving from second vgic_ops dereferencing every time. Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-04KVM: arm/arm64: Clean up vgic_retire_lr() and surroundingsPavel Fedin
1. Remove unnecessary 'irq' argument, because irq number can be retrieved from the LR. 2. Since cff9211eb1a1f58ce7f5a2d596b617928fd4be0e ("arm/arm64: KVM: Fix arch timer behavior for disabled interrupts ") LR_STATE_PENDING is queued back by vgic_retire_lr() itself. Also, it clears vlr.state itself. Therefore, we remove the same, now duplicated, check with all accompanying bit manipulations from vgic_unqueue_irqs(). 3. vgic_retire_lr() is always accompanied by vgic_irq_clear_queued(). Since it already does more than just clearing the LR, move vgic_irq_clear_queued() inside of it. Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-04KVM: arm/arm64: Optimize away redundant LR trackingPavel Fedin
Currently we use vgic_irq_lr_map in order to track which LRs hold which IRQs, and lr_used bitmap in order to track which LRs are used or free. vgic_irq_lr_map is actually used only for piggy-back optimization, and can be easily replaced by iteration over lr_used. This is good because in future, when LPI support is introduced, number of IRQs will grow up to at least 16384, while numbers from 1024 to 8192 are never going to be used. This would be a huge memory waste. In its turn, lr_used is also completely redundant since ae705930fca6322600690df9dc1c7d0516145a93 ("arm/arm64: KVM: Keep elrsr/aisr in sync with software model"), because together with lr_used we also update elrsr. This allows to easily replace lr_used with elrsr, inverting all conditions (because in elrsr '1' means 'free'). Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-03Merge branch 'irq-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "The irq departement delivers: - Rework the irqdomain core infrastructure to accomodate ACPI based systems. This is required to support ARM64 without creating artificial device tree nodes. - Sanitize the ACPI based ARM GIC initialization by making use of the new firmware independent irqdomain core - Further improvements to the generic MSI management - Generalize the irq migration on CPU hotplug - Improvements to the threaded interrupt infrastructure - Allow the migration of "chained" low level interrupt handlers - Allow optional force masking of interrupts in disable_irq[_nosysnc] - Support for two new interrupt chips - Sigh! - A larger set of errata fixes for ARM gicv3 - The usual pile of fixes, updates, improvements and cleanups all over the place" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits) Document that IRQ_NONE should be returned when IRQ not actually handled PCI/MSI: Allow the MSI domain to be device-specific PCI: Add per-device MSI domain hook of/irq: Use the msi-map property to provide device-specific MSI domain of/irq: Split of_msi_map_rid to reuse msi-map lookup irqchip/gic-v3-its: Parse new version of msi-parent property PCI/MSI: Use of_msi_get_domain instead of open-coded "msi-parent" parsing of/irq: Use of_msi_get_domain instead of open-coded "msi-parent" parsing of/irq: Add support code for multi-parent version of "msi-parent" irqchip/gic-v3-its: Add handling of PCI requester id. PCI/MSI: Add helper function pci_msi_domain_get_msi_rid(). of/irq: Add new function of_msi_map_rid() Docs: dt: Add PCI MSI map bindings irqchip/gic-v2m: Add support for multiple MSI frames irqchip/gic-v3: Fix translation of LPIs after conversion to irq_fwspec irqchip/mxs: Add Alphascale ASM9260 support irqchip/mxs: Prepare driver for hardware with different offsets irqchip/mxs: Panic if ioremap or domain creation fails irqdomain: Documentation updates irqdomain/msi: Use fwnode instead of of_node ...
2015-10-22arm/arm64: KVM: Add tracepoints for vgic and timerChristoffer Dall
The VGIC and timer code for KVM arm/arm64 doesn't have any tracepoints or tracepoint infrastructure defined. Rewriting some of the timer code handling showed me how much we need this, so let's add these simple trace points once and for all and we can easily expand with additional trace points in these files as we go along. Cc: Wei Huang <wei@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22arm/arm64: KVM: Support edge-triggered forwarded interruptsChristoffer Dall
We mark edge-triggered interrupts with the HW bit set as queued to prevent the VGIC code from injecting LRs with both the Active and Pending bits set at the same time while also setting the HW bit, because the hardware does not support this. However, this means that we must also clear the queued flag when we sync back a LR where the state on the physical distributor went from active to inactive because the guest deactivated the interrupt. At this point we must also check if the interrupt is pending on the distributor, and tell the VGIC to queue it again if it is. Since these actions on the sync path are extremely close to those for level-triggered interrupts, rename process_level_irq to process_queued_irq, allowing it to cater for both cases. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22arm/arm64: KVM: Rework the arch timer to use level-triggered semanticsChristoffer Dall
The arch timer currently uses edge-triggered semantics in the sense that the line is never sampled by the vgic and lowering the line from the timer to the vgic doesn't have any effect on the pending state of virtual interrupts in the vgic. This means that we do not support a guest with the otherwise valid behavior of (1) disable interrupts (2) enable the timer (3) disable the timer (4) enable interrupts. Such a guest would validly not expect to see any interrupts on real hardware, but will see interrupts on KVM. This patch fixes this shortcoming through the following series of changes. First, we change the flow of the timer/vgic sync/flush operations. Now the timer is always flushed/synced before the vgic, because the vgic samples the state of the timer output. This has the implication that we move the timer operations in to non-preempible sections, but that is fine after the previous commit getting rid of hrtimer schedules on every entry/exit. Second, we change the internal behavior of the timer, letting the timer keep track of its previous output state, and only lower/raise the line to the vgic when the state changes. Note that in theory this could have been accomplished more simply by signalling the vgic every time the state *potentially* changed, but we don't want to be hitting the vgic more often than necessary. Third, we get rid of the use of the map->active field in the vgic and instead simply set the interrupt as active on the physical distributor whenever the input to the GIC is asserted and conversely clear the physical active state when the input to the GIC is deasserted. Fourth, and finally, we now initialize the timer PPIs (and all the other unused PPIs for now), to be level-triggered, and modify the sync code to sample the line state on HW sync and re-inject a new interrupt if it is still pending at that time. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22arm/arm64: KVM: Use appropriate define in VGIC reset codeChristoffer Dall
We currently initialize the SGIs to be enabled in the VGIC code, but we use the VGIC_NR_PPIS define for this purpose, instead of the the more natural VGIC_NR_SGIS. Change this slightly confusing use of the defines. Note: This should have no functional change, as both names are defined to the number 16. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22arm/arm64: KVM: Implement GICD_ICFGR as RO for PPIsChristoffer Dall
The GICD_ICFGR allows the bits for the SGIs and PPIs to be read only. We currently simulate this behavior by writing a hardcoded value to the register for the SGIs and PPIs on every write of these bits to the register (ignoring what the guest actually wrote), and by writing the same value as the reset value to the register. This is a bit counter-intuitive, as the register is RO for these bits, and we can just implement it that way, allowing us to control the value of the bits purely in the reset code. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22arm/arm64: KVM: vgic: Factor out level irq processing on guest exitChristoffer Dall
Currently vgic_process_maintenance() processes dealing with a completed level-triggered interrupt directly, but we are soon going to reuse this logic for level-triggered mapped interrupts with the HW bit set, so move this logic into a separate static function. Probably the most scary part of this commit is convincing yourself that the current flow is safe compared to the old one. In the following I try to list the changes and why they are harmless: Move vgic_irq_clear_queued after kvm_notify_acked_irq: Harmless because the only potential effect of clearing the queued flag wrt. kvm_set_irq is that vgic_update_irq_pending does not set the pending bit on the emulated CPU interface or in the pending_on_cpu bitmask if the function is called with level=1. However, the point of kvm_notify_acked_irq is to call kvm_set_irq with level=0, and we set the queued flag again in __kvm_vgic_sync_hwstate later on if the level is stil high. Move vgic_set_lr before kvm_notify_acked_irq: Also, harmless because the LR are cpu-local operations and kvm_notify_acked only affects the dist Move vgic_dist_irq_clear_soft_pend after kvm_notify_acked_irq: Also harmless, because now we check the level state in the clear_soft_pend function and lower the pending bits if the level is low. Reviewed-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-20arm/arm64: KVM: Fix disabled distributor operationChristoffer Dall
We currently do a single update of the vgic state when the distributor enable/disable control register is accessed and then bypass updating the state for as long as the distributor remains disabled. This is incorrect, because updating the state does not consider the distributor enable bit, and this you can end up in a situation where an interrupt is marked as pending on the CPU interface, but not pending on the distributor, which is an impossible state to be in, and triggers a warning. Consider for example the following sequence of events: 1. An interrupt is marked as pending on the distributor - the interrupt is also forwarded to the CPU interface 2. The guest turns off the distributor (it's about to do a reboot) - we stop updating the CPU interface state from now on 3. The guest disables the pending interrupt - we remove the pending state from the distributor, but don't touch the CPU interface, see point 2. Since the distributor disable bit really means that no interrupts should be forwarded to the CPU interface, we modify the code to keep updating the internal VGIC state, but always set the CPU interface pending bits to zero when the distributor is disabled. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-20arm/arm64: KVM: Clear map->active on pend/active clearChristoffer Dall
When a guest reboots or offlines/onlines CPUs, it is not uncommon for it to clear the pending and active states of an interrupt through the emulated VGIC distributor. However, since the architected timers are defined by the architecture to be level triggered and the guest rightfully expects them to be that, but we emulate them as edge-triggered, we have to mimic level-triggered behavior for an edge-triggered virtual implementation. We currently do not signal the VGIC when the map->active field is true, because it indicates that the guest has already been signalled of the interrupt as required. Normally this field is set to false when the guest deactivates the virtual interrupt through the sync path. We also need to catch the case where the guest deactivates the interrupt through the emulated distributor, again allowing guests to boot even if the original virtual timer signal hit before the guest's GIC initialization sequence is run. Reviewed-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-20arm/arm64: KVM: Fix arch timer behavior for disabled interruptsChristoffer Dall
We have an interesting issue when the guest disables the timer interrupt on the VGIC, which happens when turning VCPUs off using PSCI, for example. The problem is that because the guest disables the virtual interrupt at the VGIC level, we never inject interrupts to the guest and therefore never mark the interrupt as active on the physical distributor. The host also never takes the timer interrupt (we only use the timer device to trigger a guest exit and everything else is done in software), so the interrupt does not become active through normal means. The result is that we keep entering the guest with a programmed timer that will always fire as soon as we context switch the hardware timer state and run the guest, preventing forward progress for the VCPU. Since the active state on the physical distributor is really part of the timer logic, it is the job of our virtual arch timer driver to manage this state. The timer->map->active boolean field indicates whether we have signalled this interrupt to the vgic and if that interrupt is still pending or active. As long as that is the case, the hardware doesn't have to generate physical interrupts and therefore we mark the interrupt as active on the physical distributor. We also have to restore the pending state of an interrupt that was queued to an LR but was retired from the LR for some reason, while remaining pending in the LR. Cc: Marc Zyngier <marc.zyngier@arm.com> Reported-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-20KVM: arm/arm64: Do not inject spurious interruptsPavel Fedin
When lowering a level-triggered line from userspace, we forgot to lower the pending bit on the emulated CPU interface and we also did not re-compute the pending_on_cpu bitmap for the CPU affected by the change. Update vgic_update_irq_pending() to fix the two issues above and also raise a warning in vgic_quue_irq_to_lr if we encounter an interrupt pending on a CPU which is neither marked active nor pending. [ Commit text reworked completely - Christoffer ] Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-09arm/arm64: KVM: Only allow 64bit hosts to build VGICv3Jean-Philippe Brucker
Hardware virtualisation of GICv3 is only supported by 64bit hosts for the moment. Some VGICv3 bits are missing from the 32bit side, and this patch allows to still be able to build 32bit hosts when CONFIG_ARM_GIC_V3 is selected. To this end, we introduce a new option, CONFIG_KVM_ARM_VGIC_V3, that is only enabled on the 64bit side. The selection is done unconditionally because CONFIG_ARM_GIC_V3 is always enabled on arm64. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-09-04arm/arm64: KVM: vgic: Move active state handling to flush_hwstateChristoffer Dall
We currently set the physical active state only when we *inject* a new pending virtual interrupt, but this is actually not correct, because we could have been preempted and run something else on the system that resets the active state to clear. This causes us to run the VM with the timer set to fire, but without setting the physical active state. The solution is to always check the LR configurations, and we if have a mapped interrupt in the LR in either the pending or active state (virtual), then set the physical active state. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-08-12KVM: arm/arm64: vgic: Prevent userspace injection of a mapped interruptMarc Zyngier
Virtual interrupts mapped to a HW interrupt should only be triggered from inside the kernel. Otherwise, you could end up confusing the kernel (and the GIC's) state machine. Rearrange the injection path so that kvm_vgic_inject_irq is used for non-mapped interrupts, and kvm_vgic_inject_mapped_irq is used for mapped interrupts. The latter should only be called from inside the kernel (timer, irqfd). Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-08-12KVM: arm/arm64: vgic: Add vgic_{get,set}_phys_irq_activeMarc Zyngier
In order to control the active state of an interrupt, introduce a pair of accessors allowing the state to be set/queried. This only affects the logical state, and the HW state will only be applied at world-switch time. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-08-12KVM: arm/arm64: vgic: Allow HW interrupts to be queued to a guestMarc Zyngier
To allow a HW interrupt to be injected into a guest, we lookup the guest virtual interrupt in the irq_phys_map list, and if we have a match, encode both interrupts in the LR. We also mark the interrupt as "active" at the host distributor level. On guest EOI on the virtual interrupt, the host interrupt will be deactivated. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-08-12KVM: arm/arm64: vgic: Allow dynamic mapping of physical/virtual interruptsMarc Zyngier
In order to be able to feed physical interrupts to a guest, we need to be able to establish the virtual-physical mapping between the two worlds. The mappings are kept in a set of RCU lists, indexed by virtual interrupts. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-08-12KVM: arm/arm64: vgic: Relax vgic_can_sample_irq for edge IRQsMarc Zyngier
We only set the irq_queued flag for level interrupts, meaning that "!vgic_irq_is_queued(vcpu, irq)" is a good enough predicate for all interrupts. This will allow us to inject edge HW interrupts, for which the state ACTIVE+PENDING is not allowed. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-06-24Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "Mostly refactoring/clean-up: - CPU ops and PSCI (Power State Coordination Interface) refactoring following the merging of the arm64 ACPI support, together with handling of Trusted (secure) OS instances - Using fixmap for permanent FDT mapping, removing the initial dtb placement requirements (within 512MB from the start of the kernel image). This required moving the FDT self reservation out of the memreserve processing - Idmap (1:1 mapping used for MMU on/off) handling clean-up - Removing flush_cache_all() - not safe on ARM unless the MMU is off. Last stages of CPU power down/up are handled by firmware already - "Alternatives" (run-time code patching) refactoring and support for immediate branch patching, GICv3 CPU interface access - User faults handling clean-up And some fixes: - Fix for VDSO building with broken ELF toolchains - Fix another case of init_mm.pgd usage for user mappings (during ASID roll-over broadcasting) - Fix for FPSIMD reloading after CPU hotplug - Fix for missing syscall trace exit - Workaround for .inst asm bug - Compat fix for switching the user tls tpidr_el0 register" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (42 commits) arm64: use private ratelimit state along with show_unhandled_signals arm64: show unhandled SP/PC alignment faults arm64: vdso: work-around broken ELF toolchains in Makefile arm64: kernel: rename __cpu_suspend to keep it aligned with arm arm64: compat: print compat_sp instead of sp arm64: mm: Fix freeing of the wrong memmap entries with !SPARSEMEM_VMEMMAP arm64: entry: fix context tracking for el0_sp_pc arm64: defconfig: enable memtest arm64: mm: remove reference to tlb.S from comment block arm64: Do not attempt to use init_mm in reset_context() arm64: KVM: Switch vgic save/restore to alternative_insn arm64: alternative: Introduce feature for GICv3 CPU interface arm64: psci: fix !CONFIG_HOTPLUG_CPU build warning arm64: fix bug for reloading FPSIMD state after CPU hotplug. arm64: kernel thread don't need to save fpsimd context. arm64: fix missing syscall trace exit arm64: alternative: Work around .inst assembler bugs arm64: alternative: Merge alternative-asm.h into alternative.h arm64: alternative: Allow immediate branch as alternative instruction arm64: Rework alternate sequence for ARM erratum 845719 ...
2015-06-18KVM: arm/arm64: vgic: Remove useless arm-gic.h #includeMarc Zyngier
Back in the days, vgic.c used to have an intimate knowledge of the actual GICv2. These days, this has been abstracted away into hardware-specific backends. Remove the now useless arm-gic.h #include directive, making it clear that GICv2 specific code doesn't belong here. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-06-17KVM: arm/arm64: vgic: Avoid injecting reserved IRQ numbersMarc Zyngier
Commit fd1d0ddf2ae9 (KVM: arm/arm64: check IRQ number on userland injection) rightly limited the range of interrupts userspace can inject in a guest, but failed to consider the (unlikely) case where a guest is configured with 1024 interrupts. In this case, interrupts ranging from 1020 to 1023 are unuseable, as they have a special meaning for the GIC CPU interface. Make sure that these number cannot be used as an IRQ. Also delete a redundant (and similarily buggy) check in kvm_set_irq. Reported-by: Peter Maydell <peter.maydell@linaro.org> Cc: Andre Przywara <andre.przywara@arm.com> Cc: <stable@vger.kernel.org> # 4.1, 4.0, 3.19, 3.18 Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-06-12arm64: KVM: Switch vgic save/restore to alternative_insnMarc Zyngier
So far, we configured the world-switch by having a small array of pointers to the save and restore functions, depending on the GIC used on the platform. Loading these values each time is a bit silly (they never change), and it makes sense to rely on the instruction patching instead. This leads to a nice cleanup of the code. Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-04-22KVM: arm/arm64: check IRQ number on userland injectionAndre Przywara
When userland injects a SPI via the KVM_IRQ_LINE ioctl we currently only check it against a fixed limit, which historically is set to 127. With the new dynamic IRQ allocation the effective limit may actually be smaller (64). So when now a malicious or buggy userland injects a SPI in that range, we spill over on our VGIC bitmaps and bytemaps memory. I could trigger a host kernel NULL pointer dereference with current mainline by injecting some bogus IRQ number from a hacked kvmtool: ----------------- .... DEBUG: kvm_vgic_inject_irq(kvm, cpu=0, irq=114, level=1) DEBUG: vgic_update_irq_pending(kvm, cpu=0, irq=114, level=1) DEBUG: IRQ #114 still in the game, writing to bytemap now... Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = ffffffc07652e000 [00000000] *pgd=00000000f658b003, *pud=00000000f658b003, *pmd=0000000000000000 Internal error: Oops: 96000006 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 1053 Comm: lkvm-msi-irqinj Not tainted 4.0.0-rc7+ #3027 Hardware name: FVP Base (DT) task: ffffffc0774e9680 ti: ffffffc0765a8000 task.ti: ffffffc0765a8000 PC is at kvm_vgic_inject_irq+0x234/0x310 LR is at kvm_vgic_inject_irq+0x30c/0x310 pc : [<ffffffc0000ae0a8>] lr : [<ffffffc0000ae180>] pstate: 80000145 ..... So this patch fixes this by checking the SPI number against the actual limit. Also we remove the former legacy hard limit of 127 in the ioctl code. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> CC: <stable@vger.kernel.org> # 4.0, 3.19, 3.18 [maz: wrap KVM_ARM_IRQ_GIC_MAX with #ifndef __KERNEL__, as suggested by Christopher Covington] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-04-22KVM: arm: irqfd: fix value returned by kvm_irq_map_gsiEric Auger
irqfd/arm curently does not support routing. kvm_irq_map_gsi is supposed to return all the routing entries associated with the provided gsi and return the number of those entries. We should return 0 at this point. Signed-off-by: Eric Auger <eric.auger@linaro.org> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-04-07Merge tag 'kvm-arm-for-4.1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into 'kvm-next' KVM/ARM changes for v4.1: - fixes for live migration - irqfd support - kvm-io-bus & vgic rework to enable ioeventfd - page ageing for stage-2 translation - various cleanups
2015-03-30KVM: arm/arm64: rework MMIO abort handling to use KVM MMIO busAndre Przywara
Currently we have struct kvm_exit_mmio for encapsulating MMIO abort data to be passed on from syndrome decoding all the way down to the VGIC register handlers. Now as we switch the MMIO handling to be routed through the KVM MMIO bus, it does not make sense anymore to use that structure already from the beginning. So we keep the data in local variables until we put them into the kvm_io_bus framework. Then we fill kvm_exit_mmio in the VGIC only, making it a VGIC private structure. On that way we replace the data buffer in that structure with a pointer pointing to a single location in a local variable, so we get rid of some copying on the way. With all of the virtual GIC emulation code now being registered with the kvm_io_bus, we can remove all of the old MMIO handling code and its dispatching functionality. I didn't bother to rename kvm_exit_mmio (to vgic_mmio or something), because that touches a lot of code lines without any good reason. This is based on an original patch by Nikolay. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Cc: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26KVM: arm/arm64: implement kvm_io_bus MMIO handling for the VGICAndre Przywara
Currently we use a lot of VGIC specific code to do the MMIO dispatching. Use the previous reworks to add kvm_io_bus style MMIO handlers. Those are not yet called by the MMIO abort handler, also the actual VGIC emulator function do not make use of it yet, but will be enabled with the following patches. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26KVM: arm/arm64: simplify vgic_find_range() and callersAndre Przywara
The vgic_find_range() function in vgic.c takes a struct kvm_exit_mmio argument, but actually only used the length field in there. Since we need to get rid of that structure in that part of the code anyway, let's rework the function (and it's callers) to pass the length argument to the function directly. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26KVM: arm/arm64: rename struct kvm_mmio_range to vgic_io_rangeAndre Przywara
The name "kvm_mmio_range" is a bit bold, given that it only covers the VGIC's MMIO ranges. To avoid confusion with kvm_io_range, rename it to vgic_io_range. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-14arm/arm64: KVM: support for un-queuing active IRQsChristoffer Dall
Migrating active interrupts causes the active state to be lost completely. This implements some additional bitmaps to track the active state on the distributor and export this to user space. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>