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path: root/arch/x86/kvm/mmu.c
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2011-01-13thp: mmu_notifier_test_youngAndrea Arcangeli
For GRU and EPT, we need gup-fast to set referenced bit too (this is why it's correct to return 0 when shadow_access_mask is zero, it requires gup-fast to set the referenced bit). qemu-kvm access already sets the young bit in the pte if it isn't zero-copy, if it's zero copy or a shadow paging EPT minor fault we relay on gup-fast to signal the page is in use... We also need to check the young bits on the secondary pagetables for NPT and not nested shadow mmu as the data may never get accessed again by the primary pte. Without this closer accuracy, we'd have to remove the heuristic that avoids collapsing hugepages in hugepage virtual regions that have not even a single subpage in use. ->test_young is full backwards compatible with GRU and other usages that don't have young bits in pagetables set by the hardware and that should nuke the secondary mmu mappings when ->clear_flush_young runs just like EPT does. Removing the heuristic that checks the young bit in khugepaged/collapse_huge_page completely isn't so bad either probably but I thought it was worth it and this makes it reliable. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13thp: kvm mmu transparent hugepage supportAndrea Arcangeli
This should work for both hugetlbfs and transparent hugepages. [akpm@linux-foundation.org: bring forward PageTransCompound() addition for bisectability] Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-12KVM: MMU: handle 'map_writable' in set_spte() functionXiao Guangrong
Move the operation of 'writable' to set_spte() to clean up code [avi: remove unneeded booleanification] Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: MMU: audit: allow audit more guests at the same timeXiao Guangrong
It only allows to audit one guest in the system since: - 'audit_point' is a glob variable - mmu_audit_disable() is called in kvm_mmu_destroy(), so audit is disabled after a guest exited this patch fix those issues then allow to audit more guests at the same time Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: Replace reads of vcpu->arch.cr3 by an accessorAvi Kivity
This allows us to keep cr3 in the VMCS, later on. Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: MMU: only write protect mappings at pagetable levelMarcelo Tosatti
If a pagetable contains a writeable large spte, all of its sptes will be write protected, including non-leaf ones, leading to endless pagefaults. Do not write protect pages above PT_PAGE_TABLE_LEVEL, as the spte fault paths assume non-leaf sptes are writable. Tested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: MMU: Initialize base_role for tdp mmusAvi Kivity
Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: SVM: copy instruction bytes from VMCBAndre Przywara
In case of a nested page fault or an intercepted #PF newer SVM implementations provide a copy of the faulting instruction bytes in the VMCB. Use these bytes to feed the instruction emulator and avoid the costly guest instruction fetch in this case. Signed-off-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: cleanup emulate_instructionAndre Przywara
emulate_instruction had many callers, but only one used all parameters. One parameter was unused, another one is now hidden by a wrapper function (required for a future addition anyway), so most callers use now a shorter parameter list. Signed-off-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: MMU: Make the way of accessing lpage_info more genericTakuya Yoshikawa
Large page information has two elements but one of them, write_count, alone is accessed by a helper function. This patch replaces this helper function with more generic one which returns newly named kvm_lpage_info structure and use it to access the other element rmap_pde. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: MMU: retry #PF for softmmuXiao Guangrong
Retry #PF for softmmu only when the current vcpu has the same cr3 as the time when #PF occurs Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: MMU: fix accessed bit set on prefault pathXiao Guangrong
Retry #PF is the speculative path, so don't set the accessed bit Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: MMU: rename 'no_apf' to 'prefault'Xiao Guangrong
It's the speculative path if 'no_apf = 1' and we will specially handle this speculative path in the later patch, so 'prefault' is better to fit the sense. Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: MMU: Avoid dropping accessed bit while removing write accessTakuya Yoshikawa
One more "KVM: MMU: Don't drop accessed bit while updating an spte." Sptes are accessed by both kvm and hardware. This patch uses update_spte() to fix the way of removing write access. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: Pull extra page fault information into struct x86_exceptionAvi Kivity
Currently page fault cr2 and nesting infomation are carried outside the fault data structure. Instead they are placed in the vcpu struct, which results in confusion as global variables are manipulated instead of passing parameters. Fix this issue by adding address and nested fields to struct x86_exception, so this struct can carry all information associated with a fault. Signed-off-by: Avi Kivity <avi@redhat.com> Tested-by: Joerg Roedel <joerg.roedel@amd.com> Tested-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: Push struct x86_exception info the various gva_to_gpa variantsAvi Kivity
Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: MMU: abstract invalid guest pte mappingXiao Guangrong
Introduce a common function to map invalid gpte Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: MMU: remove 'clear_unsync' parameterXiao Guangrong
Remove it since we can judge it by using sp->unsync Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: MMU: rename 'reset_host_protection' to 'host_writable'Lai Jiangshan
Rename it to fit its sense better Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: MMU: don't drop spte if overwrite it from W to ROXiao Guangrong
We just need flush tlb if overwrite a writable spte with a read-only one. And we should move this operation to set_spte() for sync_page path Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: MMU: fix apf prefault if nested guest is enabledXiao Guangrong
If apf is generated in L2 guest and is completed in L1 guest, it will prefault this apf in L1 guest's mmu context. Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: MMU: support apf for nonpaing guestXiao Guangrong
Let's support apf for nonpaing guest Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: MMU: fix missing post sync auditXiao Guangrong
Add AUDIT_POST_SYNC audit for long mode shadow page Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: fix tracing kvm_try_async_get_pageXiao Guangrong
Tracing 'async' and *pfn is useless, since 'async' is always true, and '*pfn' is always "fault_pfn' We can trace 'gva' and 'gfn' instead, it can help us to see the life-cycle of an async_pf Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: propagate fault r/w information to gup(), allow read-only memoryMarcelo Tosatti
As suggested by Andrea, pass r/w error code to gup(), upgrading read fault to writable if host pte allows it. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: MMU: flush TLBs on writable -> read-only spte overwriteMarcelo Tosatti
This can happen in the following scenario: vcpu0 vcpu1 read fault gup(.write=0) gup(.write=1) reuse swap cache, no COW set writable spte use writable spte set read-only spte Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: MMU: remove kvm_mmu_set_base_ptesMarcelo Tosatti
Unused. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@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: 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: 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>
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>
2010-11-05KVM: 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>
2010-10-24KVM: 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: 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: 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: 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: 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: 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: 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: MMU: fix counting of rmap entries in rmap_add()Hillf Danton
It seems that rmap entries are under counted. Signed-off-by: Hillf Danton <dhillf@gmail.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM: MMU: Fix regression with ept memory types merged into non-ept page tablesAvi Kivity
Commit "KVM: MMU: Make tdp_enabled a mmu-context parameter" made real-mode set ->direct_map, and changed the code that merges in the memory type depend on direct_map instead of tdp_enabled. However, in this case what really matters is tdp, not direct_map, since tdp changes the pte format regardless of whether the mapping is direct or not. As a result, real-mode shadow mappings got corrupted with ept memory types. The result was a huge slowdown, likely due to the cache being disabled. Change it back as the simplest fix for the regression (real fix is to move all that to vmx code, and not use tdp_enabled as a synonym for ept). Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: SVM: Initialize Nested Nested MMU context on VMRUNJoerg Roedel
This patch adds code to initialize the Nested Nested Paging MMU context when the L1 guest executes a VMRUN instruction and has nested paging enabled in its VMCB. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: Track NX state in struct kvm_mmuJoerg Roedel
With Nested Paging emulation the NX state between the two MMU contexts may differ. To make sure that always the right fault error code is recorded this patch moves the NX state into struct kvm_mmu so that the code can distinguish between L1 and L2 NX state. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: Allow long mode shadows for legacy page tablesJoerg Roedel
Currently the KVM softmmu implementation can not shadow a 32 bit legacy or PAE page table with a long mode page table. This is a required feature for nested paging emulation because the nested page table must alway be in host format. So this patch implements the missing pieces to allow long mode page tables for page table types. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: Refactor mmu_alloc_roots functionJoerg Roedel
This patch factors out the direct-mapping paths of the mmu_alloc_roots function into a seperate function. This makes it a lot easier to avoid all the unnecessary checks done in the shadow path which may break when running direct. In fact, this patch already fixes a problem when running PAE guests on a PAE shadow page table. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: Introduce kvm_pdptr_read_mmuJoerg Roedel
This function is implemented to load the pdptr pointers of the currently running guest (l1 or l2 guest). Therefore it takes care about the current paging mode and can read pdptrs out of l2 guest physical memory. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: Introduce init_kvm_nested_mmu()Joerg Roedel
This patch introduces the init_kvm_nested_mmu() function which is used to re-initialize the nested mmu when the l2 guest changes its paging mode. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: Implement nested gva_to_gpa functionsJoerg Roedel
This patch adds the functions to do a nested l2_gva to l1_gpa page table walk. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: X86: Introduce pointer to mmu context used for gva_to_gpaJoerg Roedel
This patch introduces the walk_mmu pointer which points to the mmu-context currently used for gva_to_gpa translations. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>