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2011-01-12KVM: SVM: Move fs/gs/ldt save/restore to heavyweight exit pathAvi Kivity
ldt is never used in the kernel context; same goes for fs (x86_64) and gs (i386). So save/restore them in the heavyweight exit path instead of the lightweight path. By itself, this doesn't buy us much, but it paves the way for moving vmload and vmsave to the heavyweight exit path, since they modify the same registers. [jan: fix copy/pase mistake on i386] Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: SVM: Move svm->host_gs_base into a separate structureAvi Kivity
More members will join it soon. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: SVM: Move guest register save out of interrupts disabled sectionAvi Kivity
Saving guest registers is just a memory copy, and does not need to be in the critical section. Move outside the critical section to improve latency a bit. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: Move KVM context switch into own functionAndi Kleen
gcc 4.5 with some special options is able to duplicate the VMX context switch asm in vmx_vcpu_run(). This results in a compile error because the inline asm sequence uses an on local label. The non local label is needed because other code wants to set up the return address. This patch moves the asm code into an own function and marks that explicitely noinline to avoid this problem. Better would be probably to just move it into an .S file. The diff looks worse than the change really is, it's all just code movement and no logic change. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: x86: Mark kvm_arch_setup_async_pf staticJan Kiszka
It has no user outside mmu.c and also no prototype. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: Send async PF when guest is not in userspace too.Gleb Natapov
If guest indicates that it can handle async pf in kernel mode too send it, but only if interrupts are enabled. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: Let host know whether the guest can handle async PF in non-userspace ↵Gleb Natapov
context. If guest can detect that it runs in non-preemptable context it can handle async PFs at any time, so let host know that it can send async PF even if guest cpu is not in userspace. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: Inject asynchronous page fault into a PV guest if page is swapped out.Gleb Natapov
Send async page fault to a PV guest if it accesses swapped out memory. Guest will choose another task to run upon receiving the fault. Allow async page fault injection only when guest is in user mode since otherwise guest may be in non-sleepable context and will not be able to reschedule. Vcpu will be halted if guest will fault on the same page again or if vcpu executes kernel code. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: Handle async PF in a guest.Gleb Natapov
When async PF capability is detected hook up special page fault handler that will handle async page fault events and bypass other page faults to regular page fault handler. Also add async PF handling to nested SVM emulation. Async PF always generates exit to L1 where vcpu thread will be scheduled out until page is available. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: Add PV MSR to enable asynchronous page faults delivery.Gleb Natapov
Guest enables async PF vcpu functionality using this MSR. Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: Add memory slot versioning and use it to provide fast guest write interfaceGleb Natapov
Keep track of memslots changes by keeping generation number in memslots structure. Provide kvm_write_guest_cached() function that skips gfn_to_hva() translation if memslots was not changed since previous invocation. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: Retry fault before vmentryGleb Natapov
When page is swapped in it is mapped into guest memory only after guest tries to access it again and generate another fault. To save this fault we can map it immediately since we know that guest is going to access the page. Do it only when tdp is enabled for now. Shadow paging case is more complicated. CR[034] and EFER registers should be switched before doing mapping and then switched back. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: Halt vcpu if page it tries to access is swapped outGleb Natapov
If a guest accesses swapped out memory do not swap it in from vcpu thread context. Schedule work to do swapping and put vcpu into halted state instead. Interrupts will still be delivered to the guest and if interrupt will cause reschedule guest will continue to run another task. [avi: remove call to get_user_pages_noio(), nacked by Linus; this makes everything synchrnous again] Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-07Merge branch 'for-2.6.38' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu * 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits) gameport: use this_cpu_read instead of lookup x86: udelay: Use this_cpu_read to avoid address calculation x86: Use this_cpu_inc_return for nmi counter x86: Replace uses of current_cpu_data with this_cpu ops x86: Use this_cpu_ops to optimize code vmstat: User per cpu atomics to avoid interrupt disable / enable irq_work: Use per cpu atomics instead of regular atomics cpuops: Use cmpxchg for xchg to avoid lock semantics x86: this_cpu_cmpxchg and this_cpu_xchg operations percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support percpu,x86: relocate this_cpu_add_return() and friends connector: Use this_cpu operations xen: Use this_cpu_inc_return taskstats: Use this_cpu_ops random: Use this_cpu_inc_return fs: Use this_cpu_inc_return in buffer.c highmem: Use this_cpu_xx_return() operations vmstat: Use this_cpu_inc_return for vm statistics x86: Support for this_cpu_add, sub, dec, inc_return percpu: Generic support for this_cpu_add, sub, dec, inc_return ... Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c} as per Tejun.
2011-01-02KVM: Don't reset mmu context unnecessarily when updating EFERAvi Kivity
The only bit of EFER that affects the mmu is NX, and this is already accounted for (LME only takes effect when changing cr0). Based on a patch by Hillf Danton. Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-02KVM: i8259: initialize isr_ackAvi Kivity
isr_ack is never initialized. So, until the first PIC reset, interrupts may fail to be injected. This can cause Windows XP to fail to boot, as reported in the fallout from the fix to https://bugzilla.kernel.org/show_bug.cgi?id=21962. Reported-and-tested-by: Nicolas Prochazka <prochazka.nicolas@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-12-30x86: Use this_cpu_ops to optimize codeTejun Heo
Go through x86 code and replace __get_cpu_var and get_cpu_var instances that refer to a scalar and are not used for address determinations. Cc: Yinghai Lu <yinghai@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-29KVM: MMU: Fix incorrect direct gfn for unpaged mode shadowAvi Kivity
We use the physical address instead of the base gfn for the four PAE page directories we use in unpaged mode. When the guest accesses an address above 1GB that is backed by a large host page, a BUG_ON() in kvm_mmu_set_gfn() triggers. Resolves: https://bugzilla.kernel.org/show_bug.cgi?id=21962 Reported-and-tested-by: Nicolas Prochazka <prochazka.nicolas@gmail.com> KVM-Stable-Tag. Signed-off-by: Avi Kivity <avi@redhat.com>
2010-12-16KVM: Fix preemption counter leak in kvm_timer_init()Avi Kivity
Based on a patch from Thomas Meyer. Signed-off-by: Avi Kivity <avi@redhat.com>
2010-12-08KVM: SVM: Do not report xsave in supported cpuidJoerg Roedel
To support xsave properly for the guest the SVM module need software support for it. As long as this is not present do not report the xsave as supported feature in cpuid. As a side-effect this patch moves the bit() helper function into the x86.h file so that it can be used in svm.c too. KVM-Stable-Tag. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-12-08KVM: Fix OSXSAVE after migrationSheng Yang
CPUID's OSXSAVE is a mirror of CR4.OSXSAVE bit. We need to update the CPUID after migration. KVM-Stable-Tag. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-11-17KVM: VMX: Fix host userspace gsbase corruptionAvi Kivity
We now use load_gs_index() to load gs safely; unfortunately this also changes MSR_KERNEL_GS_BASE, which we managed separately. This resulted in confusion and breakage running 32-bit host userspace on a 64-bit kernel. Fix by - saving guest MSR_KERNEL_GS_BASE before we we reload the host's gs - doing the host save/load unconditionally, instead of only when in guest long mode Things can be cleaned up further, but this is the minmal fix for now. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-11-17KVM: Correct ordering of ldt reload wrt fs/gs reloadAvi Kivity
If fs or gs refer to the ldt, they must be reloaded after the ldt. Reorder the code to that effect. Userspace code that uses the ldt with kvm is nonexistent, so this doesn't fix a user-visible bug. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-11-05KVM: x86: Issue smp_call_function_many with preemption disabledJan Kiszka
smp_call_function_many is specified to be called only with preemption disabled. Fulfill this requirement. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-11-05KVM: x86: fix information leak to userlandVasiliy Kulikov
Structures kvm_vcpu_events, kvm_debugregs, kvm_pit_state2 and kvm_clock_data are copied to userland with some padding and reserved fields unitialized. It leads to leaking of contents of kernel stack memory. We have to initialize them to zero. In patch v1 Jan Kiszka suggested to fill reserved fields with zeros instead of memset'ting the whole struct. It makes sense as these fields are explicitly marked as padding. No more fields need zeroing. KVM-Stable-Tag. Signed-off-by: Vasiliy Kulikov <segooon@gmail.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-11-05KVM: MMU: fix rmap_remove on non present sptesMarcelo Tosatti
drop_spte should not attempt to rmap_remove a non present shadow pte. This fixes a BUG_ON seen on kvm-autotest. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Reported-by: Lucas Meneghel Rodrigues <lmr@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-11-05KVM: Write protect memory after slot swapMichael S. Tsirkin
I have observed the following bug trigger: 1. userspace calls GET_DIRTY_LOG 2. kvm_mmu_slot_remove_write_access is called and makes a page ro 3. page fault happens and makes the page writeable fault is logged in the bitmap appropriately 4. kvm_vm_ioctl_get_dirty_log swaps slot pointers a lot of time passes 5. guest writes into the page 6. userspace calls GET_DIRTY_LOG At point (5), bitmap is clean and page is writeable, thus, guest modification of memory is not logged and GET_DIRTY_LOG returns an empty bitmap. The rule is that all pages are either dirty in the current bitmap, or write-protected, which is violated here. It seems that just moving kvm_mmu_slot_remove_write_access down to after the slot pointer swap should fix this bug. KVM-Stable-Tag. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24Merge branch 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
* 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (321 commits) KVM: Drop CONFIG_DMAR dependency around kvm_iommu_map_pages KVM: Fix signature of kvm_iommu_map_pages stub KVM: MCE: Send SRAR SIGBUS directly KVM: MCE: Add MCG_SER_P into KVM_MCE_CAP_SUPPORTED KVM: fix typo in copyright notice KVM: Disable interrupts around get_kernel_ns() KVM: MMU: Avoid sign extension in mmu_alloc_direct_roots() pae root address KVM: MMU: move access code parsing to FNAME(walk_addr) function KVM: MMU: audit: check whether have unsync sps after root sync KVM: MMU: audit: introduce audit_printk to cleanup audit code KVM: MMU: audit: unregister audit tracepoints before module unloaded KVM: MMU: audit: fix vcpu's spte walking KVM: MMU: set access bit for direct mapping KVM: MMU: cleanup for error mask set while walk guest page table KVM: MMU: update 'root_hpa' out of loop in PAE shadow path KVM: x86 emulator: Eliminate compilation warning in x86_decode_insn() KVM: x86: Fix constant type in kvm_get_time_scale KVM: VMX: Add AX to list of registers clobbered by guest switch KVM guest: Move a printk that's using the clock before it's ready KVM: x86: TSC catchup mode ...
2010-10-24KVM: MCE: Send SRAR SIGBUS directlyHuang Ying
Originally, SRAR SIGBUS is sent to QEMU-KVM via touching the poisoned page. But commit 96054569190bdec375fe824e48ca1f4e3b53dd36 prevents the signal from being sent. So now the signal is sent via force_sig_info_fault directly. [marcelo: use send_sig_info instead] Reported-by: Dean Nelson <dnelson@redhat.com> Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM: MCE: Add MCG_SER_P into KVM_MCE_CAP_SUPPORTEDHuang Ying
Now we have MCG_SER_P (and corresponding SRAO/SRAR MCE) support in kernel and QEMU-KVM, the MCG_SER_P should be added into KVM_MCE_CAP_SUPPORTED to make all these code really works. Reported-by: Dean Nelson <dnelson@redhat.com> Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM: fix typo in copyright noticeNicolas Kaiser
Fix typo in copyright notice. Signed-off-by: Nicolas Kaiser <nikai@nikai.net> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM: Disable interrupts around get_kernel_ns()Avi Kivity
get_kernel_ns() wants preemption disabled. It doesn't make a lot of sense during the get/set ioctls (no way to make them non-racy) but the callee wants it. Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: Avoid sign extension in mmu_alloc_direct_roots() pae root addressAvi Kivity
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: move access code parsing to FNAME(walk_addr) functionXiao Guangrong
Move access code parsing from caller site to FNAME(walk_addr) function Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: audit: check whether have unsync sps after root syncXiao Guangrong
After root synced, all unsync sps are synced, this patch add a check to make sure it's no unsync sps in VCPU's page table Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: audit: introduce audit_printk to cleanup audit codeXiao Guangrong
Introduce audit_printk, and record audit point instead audit name Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: audit: unregister audit tracepoints before module unloadedXiao Guangrong
fix: Call Trace: [<ffffffffa01e46ba>] ? kvm_mmu_pte_write+0x229/0x911 [kvm] [<ffffffffa01c6ba9>] ? gfn_to_memslot+0x39/0xa0 [kvm] [<ffffffffa01c6c26>] ? mark_page_dirty+0x16/0x2e [kvm] [<ffffffffa01c6d6f>] ? kvm_write_guest_page+0x67/0x7f [kvm] [<ffffffff81066fbd>] ? local_clock+0x2a/0x3b [<ffffffffa01d52ce>] emulator_write_phys+0x46/0x54 [kvm] ...... Code: Bad RIP value. RIP [<ffffffffa0172056>] 0xffffffffa0172056 RSP <ffff880134f69a70> CR2: ffffffffa0172056 Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: audit: fix vcpu's spte walkingXiao Guangrong
After nested nested paging, it may using long mode to shadow 32/PAE paging guest, so this patch fix it Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: set access bit for direct mappingXiao Guangrong
Set access bit while setup up direct page table if it's nonpaing or npt enabled, it's good for CPU's speculate access Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: cleanup for error mask set while walk guest page tableXiao Guangrong
Small cleanup for set page fault error code Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: update 'root_hpa' out of loop in PAE shadow pathXiao Guangrong
The value of 'vcpu->arch.mmu.pae_root' is not modified, so we can update 'root_hpa' out of the loop. Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: x86 emulator: Eliminate compilation warning in x86_decode_insn()Sheng Yang
Eliminate: arch/x86/kvm/emulate.c:801: warning: ‘sv’ may be used uninitialized in this function on gcc 4.1.2 Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM: x86: Fix constant type in kvm_get_time_scaleJan Kiszka
Older gcc versions complain about the improper type (for x86-32), 4.5 seems to fix this silently. However, we should better use the right type initially. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: VMX: Add AX to list of registers clobbered by guest switchJan Kiszka
By chance this caused no harm so far. We overwrite AX during switch to/from guest context, so we must declare this. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: x86: TSC catchup modeZachary Amsden
Negate the effects of AN TYM spell while kvm thread is preempted by tracking conversion factor to the highest TSC rate and catching the TSC up when it has fallen behind the kernel view of time. Note that once triggered, we don't turn off catchup mode. A slightly more clever version of this is possible, which only does catchup when TSC rate drops, and which specifically targets only CPUs with broken TSC, but since these all are considered unstable_tsc(), this patch covers all necessary cases. Signed-off-by: Zachary Amsden <zamsden@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM: x86: Rename timer functionZachary Amsden
This just changes some names to better reflect the usage they will be given. Separated out to keep confusion to a minimum. Signed-off-by: Zachary Amsden <zamsden@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM: x86: Make math work for other scalesZachary Amsden
The math in kvm_get_time_scale relies on the fact that NSEC_PER_SEC < 2^32. To use the same function to compute arbitrary time scales, we must extend the first reduction step to shrink the base rate to a 32-bit value, and possibly reduce the scaled rate into a 32-bit as well. Note we must take care to avoid an arithmetic overflow when scaling up the tps32 value (this could not happen with the fixed scaled value of NSEC_PER_SEC, but can happen with scaled rates above 2^31. Signed-off-by: Zachary Amsden <zamsden@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM: VMX: Respect interrupt window in big real modeAvi Kivity
If an interrupt is pending, we need to stop emulation so we can inject it. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM: VMX: Emulated real mode interrupt injectionMohammed Gamal
Replace the inject-as-software-interrupt hack we currently have with emulated injection. Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM: Add kvm_inject_realmode_interrupt() wrapperMohammed Gamal
This adds a wrapper function kvm_inject_realmode_interrupt() around the emulator function emulate_int_real() to allow real mode interrupt injection. [avi: initialize operand and address sizes before emulating interrupts] [avi: initialize rip for real mode interrupt injection] [avi: clear interrupt pending flag after emulating interrupt injection] Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>