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2017-06-22arm/arm64: KVM: add guest SEA supportTyler Baicar
Currently external aborts are unsupported by the guest abort handling. Add handling for SEAs so that the host kernel reports SEAs which occur in the guest kernel. When an SEA occurs in the guest kernel, the guest exits and is routed to kvm_handle_guest_abort(). Prior to this patch, a print message of an unsupported FSC would be printed and nothing else would happen. With this patch, the code gets routed to the APEI handling of SEAs in the host kernel to report the SEA information. Signed-off-by: Tyler Baicar <tbaicar@codeaurora.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-06-22KVM: arm/arm64: Signal SIGBUS when stage2 discovers hwpoison memoryJames Morse
Once we enable ARCH_SUPPORTS_MEMORY_FAILURE on arm64, notifications for broken memory can call memory_failure() in mm/memory-failure.c to offline pages of memory, possibly signalling user space processes and notifying all the in-kernel users. memory_failure() has two modes, early and late. Early is used by machine-managers like Qemu to receive a notification when a memory error is notified to the host. These can then be relayed to the guest before the affected page is accessed. To enable this, the process must set PR_MCE_KILL_EARLY in PR_MCE_KILL_SET using the prctl() syscall. Once the early notification has been handled, nothing stops the machine-manager or guest from accessing the affected page. If the machine-manager does this the page will fail to be mapped and SIGBUS will be sent. This patch adds the equivalent path for when the guest accesses the page, sending SIGBUS to the machine-manager. These two signals can be distinguished by the machine-manager using their si_code: BUS_MCEERR_AO for 'action optional' early notifications, and BUS_MCEERR_AR for 'action required' synchronous/late notifications. Do as x86 does, and deliver the SIGBUS when we discover pfn == KVM_PFN_ERR_HWPOISON. Use the hugepage size as si_addr_lsb if this vma was allocated as a hugepage. Transparent hugepages will be split by memory_failure() before we see them here. Cc: Punit Agrawal <punit.agrawal@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-20sched/wait: Rename wait_queue_t => wait_queue_entry_tIngo Molnar
Rename: wait_queue_t => wait_queue_entry_t 'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue", but in reality it's a queue *entry*. The 'real' queue is the wait queue head, which had to carry the name. Start sorting this out by renaming it to 'wait_queue_entry_t'. This also allows the real structure name 'struct __wait_queue' to lose its double underscore and become 'struct wait_queue_entry', which is the more canonical nomenclature for such data types. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-15KVM: ARM64: fix phy counter access failure in guest.Hu Huajun
When reading the cntpct_el0 in guest with VHE (Virtual Host Extension) enabled in host, the "Unsupported guest sys_reg access" error reported. The reason is cnthctl_el2.EL1PCTEN is not enabled, which is expected to be done in kvm_timer_init_vhe(). The problem is kvm_timer_init_vhe is called by cpu_init_hyp_mode, and which is called when VHE is disabled. This patch remove the incorrect call to kvm_timer_init_vhe() from cpu_init_hyp_mode(), and calls kvm_timer_init_vhe() to enable cnthctl_el2.EL1PCTEN in cpu_hyp_reinit(). Fixes: 488f94d7212b ("KVM: arm64: Access CNTHCTL_EL2 bit fields correctly on VHE systems") Cc: stable@vger.kernel.org Signed-off-by: Hu Huajun <huhuajun@huawei.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15arm64/kvm: sysreg: fix typo'd SYS_ICC_IGRPEN*_EL1Mark Rutland
Per ARM DDI 0487B.a, the registers are named ICC_IGRPEN*_EL1 rather than ICC_GRPEN*_EL1. Correct our mnemonics and comments to match, before we add more GICv3 register definitions. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: kvmarm@lists.cs.columbia.edu Acked-by: Christoffer Dall <cdall@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: Log an error if trapping a write-to-read-only GICv3 accessMarc Zyngier
A write-to-read-only GICv3 access should UNDEF at EL1. But since we're in complete paranoia-land with broken CPUs, let's assume the worse and gracefully handle the case. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: Log an error if trapping a read-from-write-only GICv3 accessMarc Zyngier
A read-from-write-only GICv3 access should UNDEF at EL1. But since we're in complete paranoia-land with broken CPUs, let's assume the worse and gracefully handle the case. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Log which GICv3 system registers are trappedMarc Zyngier
In order to facilitate debug, let's log which class of GICv3 system registers are trapped. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Acked-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: Enable GICv3 common sysreg trapping via command-lineMarc Zyngier
Now that we're able to safely handle common sysreg access, let's give the user the opportunity to enable it by passing a specific command-line option (vgic_v3.common_trap). Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Add ICV_PMR_EL1 handlerMarc Zyngier
Add a handler for reading/writing the guest's view of the ICC_PMR_EL1 register, which is located in the ICH_VMCR_EL2.VPMR field. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Acked-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Add ICV_CTLR_EL1 handlerMarc Zyngier
Add a handler for reading/writing the guest's view of the ICV_CTLR_EL1 register. only EOIMode and CBPR are of interest here, as all the other bits directly come from ICH_VTR_EL2 and are Read-Only. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Acked-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Add ICV_RPR_EL1 handlerMarc Zyngier
Add a handler for reading the guest's view of the ICV_RPR_EL1 register, returning the highest active priority. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Acked-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Add ICV_DIR_EL1 handlerMarc Zyngier
Add a handler for writing the guest's view of the ICC_DIR_EL1 register, performing the deactivation of an interrupt if EOImode is set ot 1. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15arm64: Add workaround for Cavium Thunder erratum 30115David Daney
Some Cavium Thunder CPUs suffer a problem where a KVM guest may inadvertently cause the host kernel to quit receiving interrupts. Use the Group-0/1 trapping in order to deal with it. [maz]: Adapted patch to the Group-0/1 trapping, reworked commit log Tested-by: Alexander Graf <agraf@suse.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: Enable GICv3 Group-0 sysreg trapping via command-lineMarc Zyngier
Now that we're able to safely handle Group-0 sysreg access, let's give the user the opportunity to enable it by passing a specific command-line option (vgic_v3.group0_trap). Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Enable trapping of Group-0 system registersMarc Zyngier
In order to be able to trap Group-0 GICv3 system registers, we need to set ICH_HCR_EL2.TALL0 begore entering the guest. This is conditionnaly done after having restored the guest's state, and cleared on exit. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Acked-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Add misc Group-0 handlersMarc Zyngier
A number of Group-0 registers can be handled by the same accessors as that of Group-1, so let's add the required system register encodings and catch them in the dispatching function. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Acked-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Add ICV_IGNREN0_EL1 handlerMarc Zyngier
Add a handler for reading/writing the guest's view of the ICC_IGRPEN0_EL1 register, which is located in the ICH_VMCR_EL2.VENG0 field. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Add ICV_BPR0_EL1 handlerMarc Zyngier
Add a handler for reading/writing the guest's view of the ICC_BPR0_EL1 register, which is located in the ICH_VMCR_EL2.BPR0 field. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: Enable GICv3 Group-1 sysreg trapping via command-lineMarc Zyngier
Now that we're able to safely handle Group-1 sysreg access, let's give the user the opportunity to enable it by passing a specific command-line option (vgic_v3.group1_trap). Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Enable trapping of Group-1 system registersMarc Zyngier
In order to be able to trap Group-1 GICv3 system registers, we need to set ICH_HCR_EL2.TALL1 before entering the guest. This is conditionally done after having restored the guest's state, and cleared on exit. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Acked-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Add ICV_HPPIR1_EL1 handlerMarc Zyngier
Add a handler for reading the guest's view of the ICV_HPPIR1_EL1 register. This is a simple parsing of the available LRs, extracting the highest available interrupt. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Add ICV_AP1Rn_EL1 handlerMarc Zyngier
Add a handler for reading/writing the guest's view of the ICV_AP1Rn_EL1 registers. We just map them to the corresponding ICH_AP1Rn_EL2 registers. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Add ICV_EOIR1_EL1 handlerMarc Zyngier
Add a handler for writing the guest's view of the ICC_EOIR1_EL1 register. This involves dropping the priority of the interrupt, and deactivating it if required (EOImode == 0). Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Add ICV_IAR1_EL1 handlerMarc Zyngier
Add a handler for reading the guest's view of the ICC_IAR1_EL1 register. This involves finding the highest priority Group-1 interrupt, checking against both PMR and the active group priority, activating the interrupt and setting the group priority as active. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Add ICV_IGRPEN1_EL1 handlerMarc Zyngier
Add a handler for reading/writing the guest's view of the ICC_IGRPEN1_EL1 register, which is located in the ICH_VMCR_EL2.VENG1 field. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Add ICV_BPR1_EL1 handlerMarc Zyngier
Add a handler for reading/writing the guest's view of the ICC_BPR1_EL1 register, which is located in the ICH_VMCR_EL2.BPR1 field. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: vgic-v3: Add hook to handle guest GICv3 sysreg accesses at EL2Marc Zyngier
In order to start handling guest access to GICv3 system registers, let's add a hook that will get called when we trap a system register access. This is gated by a new static key (vgic_v3_cpuif_trap). Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm64: Make kvm_condition_valid32() accessible from EL2Marc Zyngier
As we're about to trap CP15 accesses and handle them at EL2, we need to evaluate whether or not the condition flags are valid, as an implementation is allowed to trap despite the condition not being met. Tagging the function as __hyp_text allows this. We still rely on the cc_map array to be mapped at EL2 by virtue of being "const", and the linker to only emit relative references. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15KVM: arm/arm64: vgic-v3: Add accessors for the ICH_APxRn_EL2 registersMarc Zyngier
As we're about to access the Active Priority registers a lot more, let's define accessors that take the register number as a parameter. Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15Merge branch 'kvmarm-master/master' into HEADMarc Zyngier
2017-06-08KVM: arm/arm64: Don't assume initialized vgic when setting PMU IRQChristoffer Dall
The PMU IRQ number is set through the VCPU device's KVM_SET_DEVICE_ATTR ioctl handler for the KVM_ARM_VCPU_PMU_V3_IRQ attribute, but there is no enforced or stated requirement that this must happen after initializing the VGIC. As a result, calling vgic_valid_spi() which relies on the nr_spis being set during the VGIC init can incorrectly fail. Introduce irq_is_spi, which determines if an IRQ number is within the SPI range without verifying it against the actual VGIC properties. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-08KVM: arm/arm64: Disallow userspace control of in-kernel IRQ linesChristoffer Dall
When injecting an IRQ to the VGIC, you now have to present an owner token for that IRQ line to show that you are the owner of that line. IRQ lines driven from userspace or via an irqfd do not have an owner and will simply pass a NULL pointer. Also get rid of the unused kvm_vgic_inject_mapped_irq prototype. Signed-off-by: Christoffer Dall <cdall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-08KVM: arm/arm64: Check if irq lines to the GIC are already usedChristoffer Dall
We check if other in-kernel devices have already been connected to the GIC for a particular interrupt line when possible. For the PMU, we can do this whenever setting the PMU interrupt number from userspace. For the timers, we have to wait until we try to enable the timer, because we have a concept of default IRQ numbers that userspace shouldn't have to work around in the initialization phase. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-08KVM: arm/arm64: Introduce an allocator for in-kernel irq linesChristoffer Dall
Having multiple devices being able to signal the same interrupt line is very confusing and almost certainly guarantees a configuration error. Therefore, introduce a very simple allocator which allows a device to claim an interrupt line from the vgic for a given VM. Signed-off-by: Christoffer Dall <cdall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-08KVM: arm/arm64: Allow setting the timer IRQ numbers from userspaceChristoffer Dall
First we define an ABI using the vcpu devices that lets userspace set the interrupt numbers for the various timers on both the 32-bit and 64-bit KVM/ARM implementations. Second, we add the definitions for the groups and attributes introduced by the above ABI. (We add the PMU define on the 32-bit side as well for symmetry and it may get used some day.) Third, we set up the arch-specific vcpu device operation handlers to call into the timer code for anything related to the KVM_ARM_VCPU_TIMER_CTRL group. Fourth, we implement support for getting and setting the timer interrupt numbers using the above defined ABI in the arch timer code. Fifth, we introduce error checking upon enabling the arch timer (which is called when first running a VCPU) to check that all VCPUs are configured to use the same PPI for the timer (as mandated by the architecture) and that the virtual and physical timers are not configured to use the same IRQ number. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-08KVM: arm/arm64: Move timer IRQ default init to arch_timer.cChristoffer Dall
We currently initialize the arch timer IRQ numbers from the reset code, presumably because we once intended to model multiple CPU or SoC types from within the kernel and have hard-coded reset values in the reset code. As we are moving towards userspace being in charge of more fine-grained CPU emulation and stitching together the pieces needed to emulate a particular type of CPU, we should no longer have a tight coupling between resetting a VCPU and setting IRQ numbers. Therefore, move the logic to define and use the default IRQ numbers to the timer code and set the IRQ number immediately when creating the VCPU. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-08KVM: arm/arm64: Move irq_is_ppi() to header fileChristoffer Dall
We are about to need this define in the arch timer code as well so move it to a common location. Signed-off-by: Christoffer Dall <cdall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-08KVM: arm64: Allow creating the PMU without the in-kernel GICChristoffer Dall
Since we got support for devices in userspace which allows reporting the PMU overflow output status to userspace, we should actually allow creating the PMU on systems without an in-kernel irqchip, which in turn requires us to slightly clarify error codes for the ABI and move things around for the initialization phase. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-06KVM: arm/arm64: Handle possible NULL stage2 pud when ageing pagesMarc Zyngier
Under memory pressure, we start ageing pages, which amounts to parsing the page tables. Since we don't want to allocate any extra level, we pass NULL for our private allocation cache. Which means that stage2_get_pud() is allowed to fail. This results in the following splat: [ 1520.409577] Unable to handle kernel NULL pointer dereference at virtual address 00000008 [ 1520.417741] pgd = ffff810f52fef000 [ 1520.421201] [00000008] *pgd=0000010f636c5003, *pud=0000010f56f48003, *pmd=0000000000000000 [ 1520.429546] Internal error: Oops: 96000006 [#1] PREEMPT SMP [ 1520.435156] Modules linked in: [ 1520.438246] CPU: 15 PID: 53550 Comm: qemu-system-aar Tainted: G W 4.12.0-rc4-00027-g1885c397eaec #7205 [ 1520.448705] Hardware name: FOXCONN R2-1221R-A4/C2U4N_MB, BIOS G31FB12A 10/26/2016 [ 1520.463726] task: ffff800ac5fb4e00 task.stack: ffff800ce04e0000 [ 1520.469666] PC is at stage2_get_pmd+0x34/0x110 [ 1520.474119] LR is at kvm_age_hva_handler+0x44/0xf0 [ 1520.478917] pc : [<ffff0000080b137c>] lr : [<ffff0000080b149c>] pstate: 40000145 [ 1520.486325] sp : ffff800ce04e33d0 [ 1520.489644] x29: ffff800ce04e33d0 x28: 0000000ffff40064 [ 1520.494967] x27: 0000ffff27e00000 x26: 0000000000000000 [ 1520.500289] x25: ffff81051ba65008 x24: 0000ffff40065000 [ 1520.505618] x23: 0000ffff40064000 x22: 0000000000000000 [ 1520.510947] x21: ffff810f52b20000 x20: 0000000000000000 [ 1520.516274] x19: 0000000058264000 x18: 0000000000000000 [ 1520.521603] x17: 0000ffffa6fe7438 x16: ffff000008278b70 [ 1520.526940] x15: 000028ccd8000000 x14: 0000000000000008 [ 1520.532264] x13: ffff7e0018298000 x12: 0000000000000002 [ 1520.537582] x11: ffff000009241b93 x10: 0000000000000940 [ 1520.542908] x9 : ffff0000092ef800 x8 : 0000000000000200 [ 1520.548229] x7 : ffff800ce04e36a8 x6 : 0000000000000000 [ 1520.553552] x5 : 0000000000000001 x4 : 0000000000000000 [ 1520.558873] x3 : 0000000000000000 x2 : 0000000000000008 [ 1520.571696] x1 : ffff000008fd5000 x0 : ffff0000080b149c [ 1520.577039] Process qemu-system-aar (pid: 53550, stack limit = 0xffff800ce04e0000) [...] [ 1521.510735] [<ffff0000080b137c>] stage2_get_pmd+0x34/0x110 [ 1521.516221] [<ffff0000080b149c>] kvm_age_hva_handler+0x44/0xf0 [ 1521.522054] [<ffff0000080b0610>] handle_hva_to_gpa+0xb8/0xe8 [ 1521.527716] [<ffff0000080b3434>] kvm_age_hva+0x44/0xf0 [ 1521.532854] [<ffff0000080a58b0>] kvm_mmu_notifier_clear_flush_young+0x70/0xc0 [ 1521.539992] [<ffff000008238378>] __mmu_notifier_clear_flush_young+0x88/0xd0 [ 1521.546958] [<ffff00000821eca0>] page_referenced_one+0xf0/0x188 [ 1521.552881] [<ffff00000821f36c>] rmap_walk_anon+0xec/0x250 [ 1521.558370] [<ffff000008220f78>] rmap_walk+0x78/0xa0 [ 1521.563337] [<ffff000008221104>] page_referenced+0x164/0x180 [ 1521.569002] [<ffff0000081f1af0>] shrink_active_list+0x178/0x3b8 [ 1521.574922] [<ffff0000081f2058>] shrink_node_memcg+0x328/0x600 [ 1521.580758] [<ffff0000081f23f4>] shrink_node+0xc4/0x328 [ 1521.585986] [<ffff0000081f2718>] do_try_to_free_pages+0xc0/0x340 [ 1521.592000] [<ffff0000081f2a64>] try_to_free_pages+0xcc/0x240 [...] The trivial fix is to handle this NULL pud value early, rather than dereferencing it blindly. Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-06KVM: arm/arm64: vgic-v3: Fix nr_pre_bits bitfield extractionChristoffer Dall
We used to extract PRIbits from the ICH_VT_EL2 which was the upper field in the register word, so a mask wasn't necessary, but as we switched to looking at PREbits, which is bits 26 through 28 with the PRIbits field being potentially non-zero, we really need to mask off the field value, otherwise fun things may happen. Signed-off-by: Christoffer Dall <cdall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-04KVM: arm/arm64: timer: remove request-less vcpu kickAndrew Jones
The timer work is only scheduled for a VCPU when that VCPU is blocked. This means we only need to wake it up, not kick (IPI) it. While calling kvm_vcpu_kick() would just do the wake up, and not kick, anyway, let's change this to avoid request-less vcpu kicks, as they're generally not a good idea (see "Request-less VCPU Kicks" in Documentation/virtual/kvm/vcpu-requests.rst) Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-04KVM: arm/arm64: PMU: remove request-less vcpu kickAndrew Jones
Refactor PMU overflow handling in order to remove the request-less vcpu kick. Now, since kvm_vgic_inject_irq() uses vcpu requests, there should be no chance that a kick sent at just the wrong time (between the VCPU's call to kvm_pmu_flush_hwstate() and before it enters guest mode) results in a failure for the guest to see updated GIC state until its next exit some time later for some other reason. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-04KVM: arm/arm64: use vcpu requests for irq injectionAndrew Jones
Don't use request-less VCPU kicks when injecting IRQs, as a VCPU kick meant to trigger the interrupt injection could be sent while the VCPU is outside guest mode, which means no IPI is sent, and after it has called kvm_vgic_flush_hwstate(), meaning it won't see the updated GIC state until its next exit some time later for some other reason. The receiving VCPU only needs to check this request in VCPU RUN to handle it. By checking it, if it's pending, a memory barrier will be issued that ensures all state is visible. See "Ensuring Requests Are Seen" of Documentation/virtual/kvm/vcpu-requests.rst Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-04KVM: arm/arm64: change exit request to sleep requestAndrew Jones
A request called EXIT is too generic. All requests are meant to cause exits, but different requests have different flags. Let's not make it difficult to decide if the EXIT request is correct for some case by just always providing unique requests for each case. This patch changes EXIT to SLEEP, because that's what the request is asking the VCPU to do. Signed-off-by: Andrew Jones <drjones@redhat.com> Acked-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-04KVM: arm/arm64: optimize VCPU RUNAndrew Jones
We can make a small optimization by not checking the state of the power_off field on each run. This is done by treating power_off like pause, only checking it when we get the EXIT VCPU request. When a VCPU powers off another VCPU the EXIT request is already made, so we just need to make sure the request is also made on self power off. kvm_vcpu_kick() isn't necessary for these cases, as the VCPU would just be kicking itself, but we add it anyway as a self kick doesn't cost much, and it makes the code more future-proof. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-04KVM: arm/arm64: use vcpu requests for power_offAndrew Jones
System shutdown is currently using request-less VCPU kicks. This leaves open a tiny race window, as it doesn't ensure the state change to power_off is seen by a VCPU just about to enter guest mode. VCPU requests, OTOH, are guaranteed to be seen (see "Ensuring Requests Are Seen" of Documentation/virtual/kvm/vcpu-requests.rst) This patch applies the EXIT request used by pause to power_off, fixing the race. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-04KVM: arm/arm64: replace pause checks with vcpu request checksAndrew Jones
The current use of KVM_REQ_VCPU_EXIT for pause is fine. Even the requester clearing the request is OK, as this is the special case where the sole requesting thread and receiving VCPU are executing synchronously (see "Clearing Requests" in Documentation/virtual/kvm/vcpu-requests.rst) However, that's about to change, so let's ensure only the receiving VCPU clears the request. Additionally, by guaranteeing KVM_REQ_VCPU_EXIT is always set when pause is, we can avoid checking pause directly in VCPU RUN. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-04KVM: arm/arm64: properly use vcpu requestsAndrew Jones
arm/arm64 already has one VCPU request used when setting pause, but it doesn't properly check requests in VCPU RUN. Check it and also make sure we set vcpu->mode at the appropriate time (before the check) and with the appropriate barriers. See Documentation/virtual/kvm/vcpu-requests.rst. Also make sure we don't leave any vcpu requests we don't intend to handle later set in the request bitmap. If we don't clear them, then kvm_request_pending() may return true when it shouldn't. Using VCPU requests properly fixes a small race where pause could get set just as a VCPU was entering guest mode. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-04KVM: arm/arm64: Use uaccess functions for GICv3 {sc}activeChristoffer Dall
We recently rewrote the sactive and cactive handlers to take the kvm lock for guest accesses to these registers. However, when accessed from userspace this lock is already held. Unfortunately we forgot to change the private accessors for GICv3, because these are redistributor registers and not distributor registers. Signed-off-by: Christoffer Dall <cdall@linaro.org>