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2011-11-08powerpc/kvm: Fix build with older toolchainsNishanth Aravamudan
Fix KVM build for older toolchains (found with .powerpc64-unknown-linux-gnu-gcc (crosstool-NG-1.8.1) 4.3.2): AS arch/powerpc/kvm/book3s_hv_rmhandlers.o arch/powerpc/kvm/book3s_hv_rmhandlers.S: Assembler messages: arch/powerpc/kvm/book3s_hv_rmhandlers.S:1388: Error: Unrecognized opcode: `popcntw' make[1]: *** [arch/powerpc/kvm/book3s_hv_rmhandlers.o] Error 1 make: *** [_module_arch/powerpc/kvm] Error 2 Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-10-31powerpc: remove non-required uses of include <linux/module.h>Paul Gortmaker
None of the files touched here are modules, and they are not exporting any symbols either -- so there is no need to be including the module.h. Builds of all the files remains successful. Even kernel/module.c does not need to include it, since it includes linux/moduleloader.h instead. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31powerpc: various straight conversions from module.h --> export.hPaul Gortmaker
All these files were including module.h just for the basic EXPORT_SYMBOL infrastructure. We can shift them off to the export.h header which is a way smaller footprint and thus realize some compile time gains. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31powerpc: include export.h for files using EXPORT_SYMBOL/THIS_MODULEPaul Gortmaker
Fix failures in powerpc associated with the previously allowed implicit module.h presence that now lead to things like this: arch/powerpc/mm/mmu_context_hash32.c:76:1: error: type defaults to 'int' in declaration of 'EXPORT_SYMBOL_GPL' arch/powerpc/mm/tlb_hash32.c:48:1: error: type defaults to 'int' in declaration of 'EXPORT_SYMBOL' arch/powerpc/kernel/pci_32.c:51:1: error: type defaults to 'int' in declaration of 'EXPORT_SYMBOL_GPL' arch/powerpc/kernel/iomap.c:36:1: error: type defaults to 'int' in declaration of 'EXPORT_SYMBOL' arch/powerpc/platforms/44x/canyonlands.c:126:1: error: type defaults to 'int' in declaration of 'EXPORT_SYMBOL' arch/powerpc/kvm/44x.c:168:59: error: 'THIS_MODULE' undeclared (first use in this function) [with several contibutions from Stephen Rothwell <sfr@canb.auug.org.au>] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31powerpc: add export.h to files making use of EXPORT_SYMBOLPaul Gortmaker
With module.h being implicitly everywhere via device.h, the absence of explicitly including something for EXPORT_SYMBOL went unnoticed. Since we are heading to fix things up and clean module.h from the device.h file, we need to explicitly include these files now. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-09-25KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode codePaul Mackerras
With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-09-25KVM: PPC: book3s_pr: Simplify transitions between virtual and real modePaul Mackerras
This simplifies the way that the book3s_pr makes the transition to real mode when entering the guest. We now call kvmppc_entry_trampoline (renamed from kvmppc_rmcall) in the base kernel using a normal function call instead of doing an indirect call through a pointer in the vcpu. If kvm is a module, the module loader takes care of generating a trampoline as it does for other calls to functions outside the module. kvmppc_entry_trampoline then disables interrupts and jumps to kvmppc_handler_trampoline_enter in real mode using an rfi[d]. That then uses the link register as the address to return to (potentially in module space) when the guest exits. This also simplifies the way that we call the Linux interrupt handler when we exit the guest due to an external, decrementer or performance monitor interrupt. Instead of turning on the MMU, then deciding that we need to call the Linux handler and turning the MMU back off again, we now go straight to the handler at the point where we would turn the MMU on. The handler will then return to the virtual-mode code (potentially in the module). Along the way, this moves the setting and clearing of the HID5 DCBZ32 bit into real-mode interrupts-off code, and also makes sure that we clear the MSR[RI] bit before loading values into SRR0/1. The net result is that we no longer need any code addresses to be stored in vcpu->arch. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-09-25KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S separatelyPaul Mackerras
This makes arch/powerpc/kvm/book3s_rmhandlers.S and arch/powerpc/kvm/book3s_hv_rmhandlers.S be assembled as separate compilation units rather than having them #included in arch/powerpc/kernel/exceptions-64s.S. We no longer have any conditional branches between the exception prologs in exceptions-64s.S and the KVM handlers, so there is no need to keep their contents close together in the vmlinux image. In their current location, they are using up part of the limited space between the first-level interrupt handlers and the firmware NMI data area at offset 0x7000, and with some kernel configurations this area will overflow (e.g. allyesconfig), leading to an "attempt to .org backwards" error when compiling exceptions-64s.S. Moving them out requires that we add some #includes that the book3s_{,hv_}rmhandlers.S code was previously getting implicitly via exceptions-64s.S. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-09-25KVM: PPC: Add sanity checking to vcpu_runAlexander Graf
There are multiple features in PowerPC KVM that can now be enabled depending on the user's wishes. Some of the combinations don't make sense or don't work though. So this patch adds a way to check if the executing environment would actually be able to run the guest properly. It also adds sanity checks if PVR is set (should always be true given the current code flow), if PAPR is only used with book3s_64 where it works and that HV KVM is only used in PAPR mode. Signed-off-by: Alexander Graf <agraf@suse.de>
2011-09-25KVM: PPC: Enable the PAPR CAP for Book3SAlexander Graf
Now that Book3S PV mode can also run PAPR guests, we can add a PAPR cap and enable it for all Book3S targets. Enabling that CAP switches KVM into PAPR mode. Signed-off-by: Alexander Graf <agraf@suse.de>
2011-09-25KVM: PPC: Support SC1 hypercalls for PAPR in PR modeAlexander Graf
PAPR defines hypercalls as SC1 instructions. Using these, the guest modifies page tables and does other privileged operations that it wouldn't be allowed to do in supervisor mode. This patch adds support for PR KVM to trap these instructions and route them through the same PAPR hypercall interface that we already use for HV style KVM. Signed-off-by: Alexander Graf <agraf@suse.de>
2011-09-25KVM: PPC: Stub emulate CFAR and PURR SPRsAlexander Graf
Recent Linux versions use the CFAR and PURR SPRs, but don't really care about their contents (yet). So for now, we can simply return 0 when the guest wants to read them. Signed-off-by: Alexander Graf <agraf@suse.de>
2011-09-25KVM: PPC: Add PAPR hypercall code for PR modeAlexander Graf
When running a PAPR guest, we need to handle a few hypercalls in kernel space, most prominently the page table invalidation (to sync the shadows). So this patch adds handling for a few PAPR hypercalls to PR mode KVM. I tried to share the code with HV mode, but it ended up being a lot easier this way around, as the two differ too much in those details. Signed-off-by: Alexander Graf <agraf@suse.de> --- v1 -> v2: - whitespace fix
2011-09-25KVM: PPC: Add support for explicit HIOR settingAlexander Graf
Until now, we always set HIOR based on the PVR, but this is just wrong. Instead, we should be setting HIOR explicitly, so user space can decide what the initial HIOR value is - just like on real hardware. We keep the old PVR based way around for backwards compatibility, but once user space uses the SREGS based method, we drop the PVR logic. Signed-off-by: Alexander Graf <agraf@suse.de>
2011-09-25KVM: PPC: Read out syscall instruction on trapAlexander Graf
We have a few traps where we cache the instruction that cause the trap for analysis later on. Since we now need to be able to distinguish between SC 0 and SC 1 system calls and the only way to find out which is which is by looking at the instruction, we also read out the instruction causing the system call. Signed-off-by: Alexander Graf <agraf@suse.de>
2011-09-25KVM: PPC: Interpret SDR1 as HVA in PAPR modeAlexander Graf
When running a PAPR guest, the guest is not allowed to set SDR1 - instead the HTAB information is held in internal hypervisor structures. But all of our current code relies on SDR1 and walking the HTAB like on real hardware. So in order to not be too intrusive, we simply set SDR1 to the HTAB we hold in host memory. That way we can keep the HTAB in user space, but use it from kernel space to map the guest. Signed-off-by: Alexander Graf <agraf@suse.de>
2011-09-25KVM: PPC: Check privilege level on SPRsAlexander Graf
We have 3 privilege levels: problem state, supervisor state and hypervisor state. Each of them can access different SPRs, so we need to check on every SPR if it's accessible in the respective mode. Signed-off-by: Alexander Graf <agraf@suse.de>
2011-09-25KVM: PPC: move compute_tlbie_rb to book3s common headerAlexander Graf
We need the compute_tlbie_rb in _pr and _hv implementations for papr soon, so let's move it over to a common header file that both implementations can leverage. Signed-off-by: Alexander Graf <agraf@suse.de>
2011-08-05powerpc/kvm: Fix build errors with older toolchainsNishanth Aravamudan
On a box with gcc 4.3.2, I see errors like: arch/powerpc/kvm/book3s_hv_rmhandlers.S:1254: Error: Unrecognized opcode: stxvd2x arch/powerpc/kvm/book3s_hv_rmhandlers.S:1316: Error: Unrecognized opcode: lxvd2x Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-07-24Merge branch 'kvm-updates/3.1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
* 'kvm-updates/3.1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (143 commits) KVM: IOMMU: Disable device assignment without interrupt remapping KVM: MMU: trace mmio page fault KVM: MMU: mmio page fault support KVM: MMU: reorganize struct kvm_shadow_walk_iterator KVM: MMU: lockless walking shadow page table KVM: MMU: do not need atomicly to set/clear spte KVM: MMU: introduce the rules to modify shadow page table KVM: MMU: abstract some functions to handle fault pfn KVM: MMU: filter out the mmio pfn from the fault pfn KVM: MMU: remove bypass_guest_pf KVM: MMU: split kvm_mmu_free_page KVM: MMU: count used shadow pages on prepareing path KVM: MMU: rename 'pt_write' to 'emulate' KVM: MMU: cleanup for FNAME(fetch) KVM: MMU: optimize to handle dirty bit KVM: MMU: cache mmio info on page fault path KVM: x86: introduce vcpu_mmio_gva_to_gpa to cleanup the code KVM: MMU: do not update slot bitmap if spte is nonpresent KVM: MMU: fix walking shadow page table KVM guest: KVM Steal time registration ...
2011-07-23virtio: expose for non-virtualization users tooOhad Ben-Cohen
virtio has been so far used only in the context of virtualization, and the virtio Kconfig was sourced directly by the relevant arch Kconfigs when VIRTUALIZATION was selected. Now that we start using virtio for inter-processor communications, we need to source the virtio Kconfig outside of the virtualization scope too. Moreover, some architectures might use virtio for both virtualization and inter-processor communications, so directly sourcing virtio might yield unexpected results due to conflicting selections. The simple solution offered by this patch is to always source virtio's Kconfig in drivers/Kconfig, and remove it from the appropriate arch Kconfigs. Additionally, a virtio menu entry has been added so virtio drivers don't show up in the general drivers menu. This way anyone can use virtio, though it's arguably less accessible (and neat!) for virtualization users now. Note: some architectures (mips and sh) seem to have a VIRTUALIZATION menu merely for sourcing virtio's Kconfig, so that menu is removed too. Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-07-12KVM: PPC: book3s_hv: Add support for PPC970-family processorsPaul Mackerras
This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12powerpc, KVM: Split HVMODE_206 cpu feature bit into separate HV and ↵Paul Mackerras
architecture bits This replaces the single CPU_FTR_HVMODE_206 bit with two bits, one to indicate that we have a usable hypervisor mode, and another to indicate that the processor conforms to PowerISA version 2.06. We also add another bit to indicate that the processor conforms to ISA version 2.01 and set that for PPC970 and derivatives. Some PPC970 chips (specifically those in Apple machines) have a hypervisor mode in that MSR[HV] is always 1, but the hypervisor mode is not useful in the sense that there is no way to run any code in supervisor mode (HV=0 PR=0). On these processors, the LPES0 and LPES1 bits in HID4 are always 0, and we use that as a way of detecting that hypervisor mode is not useful. Where we have a feature section in assembly code around code that only applies on POWER7 in hypervisor mode, we use a construct like END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206) The definition of END_FTR_SECTION_IFSET is such that the code will be enabled (not overwritten with nops) only if all bits in the provided mask are set. Note that the CPU feature check in __tlbie() only needs to check the ARCH_206 bit, not the HVMODE bit, because __tlbie() can only get called if we are running bare-metal, i.e. in hypervisor mode. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: Allocate RMAs (Real Mode Areas) at boot for use by guestsPaul Mackerras
This adds infrastructure which will be needed to allow book3s_hv KVM to run on older POWER processors, including PPC970, which don't support the Virtual Real Mode Area (VRMA) facility, but only the Real Mode Offset (RMO) facility. These processors require a physically contiguous, aligned area of memory for each guest. When the guest does an access in real mode (MMU off), the address is compared against a limit value, and if it is lower, the address is ORed with an offset value (from the Real Mode Offset Register (RMOR)) and the result becomes the real address for the access. The size of the RMA has to be one of a set of supported values, which usually includes 64MB, 128MB, 256MB and some larger powers of 2. Since we are unlikely to be able to allocate 64MB or more of physically contiguous memory after the kernel has been running for a while, we allocate a pool of RMAs at boot time using the bootmem allocator. The size and number of the RMAs can be set using the kvm_rma_size=xx and kvm_rma_count=xx kernel command line options. KVM exports a new capability, KVM_CAP_PPC_RMA, to signal the availability of the pool of preallocated RMAs. The capability value is 1 if the processor can use an RMA but doesn't require one (because it supports the VRMA facility), or 2 if the processor requires an RMA for each guest. This adds a new ioctl, KVM_ALLOCATE_RMA, which allocates an RMA from the pool and returns a file descriptor which can be used to map the RMA. It also returns the size of the RMA in the argument structure. Having an RMA means we will get multiple KMV_SET_USER_MEMORY_REGION ioctl calls from userspace. To cope with this, we now preallocate the kvm->arch.ram_pginfo array when the VM is created with a size sufficient for up to 64GB of guest memory. Subsequently we will get rid of this array and use memory associated with each memslot instead. This moves most of the code that translates the user addresses into host pfns (page frame numbers) out of kvmppc_prepare_vrma up one level to kvmppc_core_prepare_memory_region. Also, instead of having to look up the VMA for each page in order to check the page size, we now check that the pages we get are compound pages of 16MB. However, if we are adding memory that is mapped to an RMA, we don't bother with calling get_user_pages_fast and instead just offset from the base pfn for the RMA. Typically the RMA gets added after vcpus are created, which makes it inconvenient to have the LPCR (logical partition control register) value in the vcpu->arch struct, since the LPCR controls whether the processor uses RMA or VRMA for the guest. This moves the LPCR value into the kvm->arch struct and arranges for the MER (mediated external request) bit, which is the only bit that varies between vcpus, to be set in assembly code when going into the guest if there is a pending external interrupt request. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: Allow book3s_hv guests to use SMT processor modesPaul Mackerras
This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: Accelerate H_PUT_TCE by implementing it in real modeDavid Gibson
This improves I/O performance for guests using the PAPR paravirtualization interface by making the H_PUT_TCE hcall faster, by implementing it in real mode. H_PUT_TCE is used for updating virtual IOMMU tables, and is used both for virtual I/O and for real I/O in the PAPR interface. Since this moves the IOMMU tables into the kernel, we define a new KVM_CREATE_SPAPR_TCE ioctl to allow qemu to create the tables. The ioctl returns a file descriptor which can be used to mmap the newly created table. The qemu driver models use them in the same way as userspace managed tables, but they can be updated directly by the guest with a real-mode H_PUT_TCE implementation, reducing the number of host/guest context switches during guest IO. There are certain circumstances where it is useful for userland qemu to write to the TCE table even if the kernel H_PUT_TCE path is used most of the time. Specifically, allowing this will avoid awkwardness when we need to reset the table. More importantly, we will in the future need to write the table in order to restore its state after a checkpoint resume or migration. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: Handle some PAPR hcalls in the kernelPaul Mackerras
This adds the infrastructure for handling PAPR hcalls in the kernel, either early in the guest exit path while we are still in real mode, or later once the MMU has been turned back on and we are in the full kernel context. The advantage of handling hcalls in real mode if possible is that we avoid two partition switches -- and this will become more important when we support SMT4 guests, since a partition switch means we have to pull all of the threads in the core out of the guest. The disadvantage is that we can only access the kernel linear mapping, not anything vmalloced or ioremapped, since the MMU is off. This also adds code to handle the following hcalls in real mode: H_ENTER Add an HPTE to the hashed page table H_REMOVE Remove an HPTE from the hashed page table H_READ Read HPTEs from the hashed page table H_PROTECT Change the protection bits in an HPTE H_BULK_REMOVE Remove up to 4 HPTEs from the hashed page table H_SET_DABR Set the data address breakpoint register Plus code to handle the following hcalls in the kernel: H_CEDE Idle the vcpu until an interrupt or H_PROD hcall arrives H_PROD Wake up a ceded vcpu H_REGISTER_VPA Register a virtual processor area (VPA) The code that runs in real mode has to be in the base kernel, not in the module, if KVM is compiled as a module. The real-mode code can only access the kernel linear mapping, not vmalloc or ioremap space. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: Add support for Book3S processors in hypervisor modePaul Mackerras
This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: Split host-state fields out of kvmppc_book3s_shadow_vcpuPaul Mackerras
There are several fields in struct kvmppc_book3s_shadow_vcpu that temporarily store bits of host state while a guest is running, rather than anything relating to the particular guest or vcpu. This splits them out into a new kvmppc_host_state structure and modifies the definitions in asm-offsets.c to suit. On 32-bit, we have a kvmppc_host_state structure inside the kvmppc_book3s_shadow_vcpu since the assembly code needs to be able to get to them both with one pointer. On 64-bit they are separate fields in the PACA. This means that on 64-bit we don't need to copy the kvmppc_host_state in and out on vcpu load/unload, and in future will mean that the book3s_hv code doesn't need a shadow_vcpu struct in the PACA at all. That does mean that we have to be careful not to rely on any values persisting in the hstate field of the paca across any point where we could block or get preempted. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: Move guest enter/exit down into subarch-specific codePaul Mackerras
Instead of doing the kvm_guest_enter/exit() and local_irq_dis/enable() calls in powerpc.c, this moves them down into the subarch-specific book3s_pr.c and booke.c. This eliminates an extra local_irq_enable() call in book3s_pr.c, and will be needed for when we do SMT4 guest support in the book3s hypervisor mode code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: Pass init/destroy vm and prepare/commit memory region ops downPaul Mackerras
This arranges for the top-level arch/powerpc/kvm/powerpc.c file to pass down some of the calls it gets to the lower-level subarchitecture specific code. The lower-level implementations (in booke.c and book3s.c) are no-ops. The coming book3s_hv.c will need this. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: Deliver program interrupts right away instead of queueing themPaul Mackerras
Doing so means that we don't have to save the flags anywhere and gets rid of the last reference to to_book3s(vcpu) in arch/powerpc/kvm/book3s.c. Doing so is OK because a program interrupt won't be generated at the same time as any other synchronous interrupt. If a program interrupt and an asynchronous interrupt (external or decrementer) are generated at the same time, the program interrupt will be delivered, which is correct because it has a higher priority, and then the asynchronous interrupt will be masked. We don't ever generate system reset or machine check interrupts to the guest, but if we did, then we would need to make sure they got delivered rather than the program interrupt. The current code would be wrong in this situation anyway since it would deliver the program interrupt as well as the reset/machine check interrupt. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12powerpc, KVM: Rework KVM checks in first-level interrupt handlersPaul Mackerras
Instead of branching out-of-line with the DO_KVM macro to check if we are in a KVM guest at the time of an interrupt, this moves the KVM check inline in the first-level interrupt handlers. This speeds up the non-KVM case and makes sure that none of the interrupt handlers are missing the check. Because the first-level interrupt handlers are now larger, some things had to be move out of line in exceptions-64s.S. This all necessitated some minor changes to the interrupt entry code in KVM. This also streamlines the book3s_32 KVM test. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: Split out code from book3s.c into book3s_pr.cPaul Mackerras
In preparation for adding code to enable KVM to use hypervisor mode on 64-bit Book 3S processors, this splits book3s.c into two files, book3s.c and book3s_pr.c, where book3s_pr.c contains the code that is specific to running the guest in problem state (user mode) and book3s.c contains code which should apply to all Book 3S processors. In doing this, we abstract some details, namely the interrupt offset, updating the interrupt pending flag, and detecting if the guest is in a critical section. These are all things that will be different when we use hypervisor mode. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: Move fields between struct kvm_vcpu_arch and kvmppc_vcpu_book3sPaul Mackerras
This moves the slb field, which represents the state of the emulated SLB, from the kvmppc_vcpu_book3s struct to the kvm_vcpu_arch, and the hpte_hash_[v]pte[_long] fields from kvm_vcpu_arch to kvmppc_vcpu_book3s. This is in accord with the principle that the kvm_vcpu_arch struct represents the state of the emulated CPU, and the kvmppc_vcpu_book3s struct holds the auxiliary data structures used in the emulation. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: Fix machine checks on 32-bit Book3SPaul Mackerras
Commit 69acc0d3ba ("KVM: PPC: Resolve real-mode handlers through function exports") resulted in vcpu->arch.trampoline_lowmem and vcpu->arch.trampoline_enter ending up with kernel virtual addresses rather than physical addresses. This is OK on 64-bit Book3S machines, which ignore the top 4 bits of the effective address in real mode, but on 32-bit Book3S machines, accessing these addresses in real mode causes machine check interrupts, as the hardware uses the whole effective address as the physical address in real mode. This fixes the problem by using __pa() to convert these addresses to physical addresses. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: e500: Don't search over the entire TLB0.Scott Wood
Only look in the 4 entries that could possibly contain the entry we're looking for. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: e500: Add shadow PID supportLiu Yu
Dynamically assign host PIDs to guest PIDs, splitting each guest PID into multiple host (shadow) PIDs based on kernel/user and MSR[IS/DS]. Use both PID0 and PID1 so that the shadow PIDs for the right mode can be selected, that correspond both to guest TID = zero and guest TID = guest PID. This allows us to significantly reduce the frequency of needing to invalidate the entire TLB. When the guest mode or PID changes, we just update the host PID0/PID1. And since the allocation of shadow PIDs is global, multiple guests can share the TLB without conflict. Note that KVM does not yet support the guest setting PID1 or PID2 to a value other than zero. This will need to be fixed for nested KVM to work. Until then, we enforce the requirement for guest PID1/PID2 to stay zero by failing the emulation if the guest tries to set them to something else. Signed-off-by: Liu Yu <yu.liu@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: e500: Stop keeping shadow TLBLiu Yu
Instead of a fully separate set of TLB entries, keep just the pfn and dirty status. Signed-off-by: Liu Yu <yu.liu@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: e500: enable magic pageScott Wood
This is a shared page used for paravirtualization. It is always present in the guest kernel's effective address space at the address indicated by the hypercall that enables it. The physical address specified by the hypercall is not used, as e500 does not have real mode. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: e500: Support large page mappings of PFNMAP vmas.Scott Wood
This allows large pages to be used on guest mappings backed by things like /dev/mem, resulting in a significant speedup when guest memory is mapped this way (it's useful for directly-assigned MMIO, too). This is not a substitute for hugetlbfs integration, but is useful for configurations where devices are directly assigned on chips without an IOMMU -- in these cases, we need guest physical and true physical to match, and be contiguous, so static reservation and mapping via /dev/mem is the most straightforward way to set things up. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: e500: Eliminate shadow_pages[], and use pfns instead.Scott Wood
This is in line with what other architectures do, and will allow us to map things other than ordinary, unreserved kernel pages -- such as dedicated devices, or large contiguous reserved regions. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: e500: don't use MAS0 as intermediate storage.Scott Wood
This avoids races. It also means that we use the shadow TLB way, rather than the hardware hint -- if this is a problem, we could do a tlbsx before inserting a TLB0 entry. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: e500: Disable preloading TLB1 in tlb_load().Scott Wood
Since TLB1 loading doesn't check the shadow TLB before allocating another entry, you can get duplicates. Once shadow PIDs are enabled in a later patch, we won't need to invalidate the TLB on every switch, so this optimization won't be needed anyway. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: e500: Save/restore SPE stateScott Wood
This is done lazily. The SPE save will be done only if the guest has used SPE since the last preemption or heavyweight exit. Restore will be done only on demand, when enabling MSR_SPE in the shadow MSR, in response to an SPE fault or mtmsr emulation. For SPEFSCR, Linux already switches it on context switch (non-lazily), so the only remaining bit is to save it between qemu and the guest. Signed-off-by: Liu Yu <yu.liu@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: booke: use shadow_msrScott Wood
Keep the guest MSR and the guest-mode true MSR separate, rather than modifying the guest MSR on each guest entry to produce a true MSR. Any bits which should be modified based on guest MSR must be explicitly propagated from vcpu->arch.shared->msr to vcpu->arch.shadow_msr in kvmppc_set_msr(). While we're modifying the guest entry code, reorder a few instructions to bury some load latencies. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: Resolve real-mode handlers through function exportsAlexander Graf
Up until now, Book3S KVM had variables stored in the kernel that a kernel module or the kvm code in the kernel could read from to figure out where some real mode helper functions are located. This is all unnecessary. The high bits of the EA get ignore in real mode, so we can just use the pointer as is. Also, it's a lot easier on relocations when we use the normal way of resolving the address to a function, instead of jumping through hoops. This patch fixes compilation with CONFIG_RELOCATABLE=y. Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12KVM: PPC: fix partial application of "exit timing in ticks"Stuart Yoder
When http://www.spinics.net/lists/kvm-ppc/msg02664.html was applied to produce commit b51e7aa7ed6d8d134d02df78300ab0f91cfff4d2, the removal of the conversion in add_exit_timing was left out. Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-05-23Merge branch 'kvm-updates/2.6.40' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
* 'kvm-updates/2.6.40' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (131 commits) KVM: MMU: Use ptep_user for cmpxchg_gpte() KVM: Fix kvm mmu_notifier initialization order KVM: Add documentation for KVM_CAP_NR_VCPUS KVM: make guest mode entry to be rcu quiescent state KVM: x86 emulator: Make jmp far emulation into a separate function KVM: x86 emulator: Rename emulate_grpX() to em_grpX() KVM: x86 emulator: Remove unused arg from emulate_pop() KVM: x86 emulator: Remove unused arg from writeback() KVM: x86 emulator: Remove unused arg from read_descriptor() KVM: x86 emulator: Remove unused arg from seg_override() KVM: Validate userspace_addr of memslot when registered KVM: MMU: Clean up gpte reading with copy_from_user() KVM: PPC: booke: add sregs support KVM: PPC: booke: save/restore VRSAVE (a.k.a. USPRG0) KVM: PPC: use ticks, not usecs, for exit timing KVM: PPC: fix exit accounting for SPRs, tlbwe, tlbsx KVM: PPC: e500: emulate SVR KVM: VMX: Cache vmcs segment fields KVM: x86 emulator: consolidate segment accessors KVM: VMX: Avoid reading %rip unnecessarily when handling exceptions ...
2011-05-22KVM: PPC: booke: add sregs supportScott Wood
Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>