| Message ID | 20240914011348.2558415-4-seanjc@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [GIT,PULL] KVM: x86: MMU changes for 6.12 | expand |
On Sat, Sep 14, 2024 at 3:14 AM Sean Christopherson <seanjc@google.com> wrote: > > The bulk of the changes are to clean up the thorny "unprotect and retry" mess > that grew over time. The other notable change is to support yielding in the > shadow MMU when zapping rmaps (simply a historic oversight, AFAICT). This conflicts with the "zap modified memslot only" series that is in kvm/next. The resolution is nice since it's possible to reuse the new kvm_unmap_gfn_range() diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 8cd758913282..1f59781351f9 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -7064,17 +7064,10 @@ static void kvm_mmu_zap_memslot_leafs( .end = slot->base_gfn + slot->npages, .may_block = true, }; - bool flush = false; write_lock(&kvm->mmu_lock); - if (kvm_memslots_have_rmaps(kvm)) - flush = kvm_handle_gfn_range(kvm, &range, kvm_zap_rmap); - - if (tdp_mmu_enabled) - flush = kvm_tdp_mmu_unmap_gfn_range(kvm, &range, flush); - - if (flush) + if (kvm_unmap_gfn_range(kvm, &range)) kvm_flush_remote_tlbs_memslot(kvm, slot); write_unlock(&kvm->mmu_lock); (Pardon the whitespace damage!) Paolo > The following changes since commit 47ac09b91befbb6a235ab620c32af719f8208399: > > Linux 6.11-rc4 (2024-08-18 13:17:27 -0700) > > are available in the Git repository at: > > https://github.com/kvm-x86/linux.git tags/kvm-x86-mmu-6.12 > > for you to fetch changes up to 9a5bff7f5ec2383e3edac5eda561b52e267ccbb5: > > KVM: x86/mmu: Use KVM_PAGES_PER_HPAGE() instead of an open coded equivalent (2024-09-09 20:22:08 -0700) > > ---------------------------------------------------------------- > KVM x86 MMU changes for 6.12: > > - Overhaul the "unprotect and retry" logic to more precisely identify cases > where retrying is actually helpful, and to harden all retry paths against > putting the guest into an infinite retry loop. > > - Add support for yielding, e.g. to honor NEED_RESCHED, when zapping rmaps in > the shadow MMU. > > - Refactor pieces of the shadow MMU related to aging SPTEs in prepartion for > adding MGLRU support in KVM. > > - Misc cleanups > > ---------------------------------------------------------------- > Sean Christopherson (33): > KVM: x86/mmu: Clean up function comments for dirty logging APIs > KVM: x86/mmu: Decrease indentation in logic to sync new indirect shadow page > KVM: x86/mmu: Drop pointless "return" wrapper label in FNAME(fetch) > KVM: x86/mmu: Reword a misleading comment about checking gpte_changed() > KVM: x86/mmu: Replace PFERR_NESTED_GUEST_PAGE with a more descriptive helper > KVM: x86/mmu: Trigger unprotect logic only on write-protection page faults > KVM: x86/mmu: Skip emulation on page fault iff 1+ SPs were unprotected > KVM: x86: Retry to-be-emulated insn in "slow" unprotect path iff sp is zapped > KVM: x86: Get RIP from vCPU state when storing it to last_retry_eip > KVM: x86: Store gpa as gpa_t, not unsigned long, when unprotecting for retry > KVM: x86/mmu: Apply retry protection to "fast nTDP unprotect" path > KVM: x86/mmu: Try "unprotect for retry" iff there are indirect SPs > KVM: x86: Move EMULTYPE_ALLOW_RETRY_PF to x86_emulate_instruction() > KVM: x86: Fold retry_instruction() into x86_emulate_instruction() > KVM: x86/mmu: Don't try to unprotect an INVALID_GPA > KVM: x86/mmu: Always walk guest PTEs with WRITE access when unprotecting > KVM: x86/mmu: Move event re-injection unprotect+retry into common path > KVM: x86: Remove manual pfn lookup when retrying #PF after failed emulation > KVM: x86: Check EMULTYPE_WRITE_PF_TO_SP before unprotecting gfn > KVM: x86: Apply retry protection to "unprotect on failure" path > KVM: x86: Update retry protection fields when forcing retry on emulation failure > KVM: x86: Rename reexecute_instruction()=>kvm_unprotect_and_retry_on_failure() > KVM: x86/mmu: Subsume kvm_mmu_unprotect_page() into the and_retry() version > KVM: x86/mmu: Detect if unprotect will do anything based on invalid_list > KVM: x86/mmu: WARN on MMIO cache hit when emulating write-protected gfn > KVM: x86/mmu: Move walk_slot_rmaps() up near for_each_slot_rmap_range() > KVM: x86/mmu: Plumb a @can_yield parameter into __walk_slot_rmaps() > KVM: x86/mmu: Add a helper to walk and zap rmaps for a memslot > KVM: x86/mmu: Honor NEED_RESCHED when zapping rmaps and blocking is allowed > KVM: x86/mmu: Morph kvm_handle_gfn_range() into an aging specific helper > KVM: x86/mmu: Fold mmu_spte_age() into kvm_rmap_age_gfn_range() > KVM: x86/mmu: Add KVM_RMAP_MANY to replace open coded '1' and '1ul' literals > KVM: x86/mmu: Use KVM_PAGES_PER_HPAGE() instead of an open coded equivalent > > arch/x86/include/asm/kvm_host.h | 14 +- > arch/x86/kvm/mmu/mmu.c | 522 ++++++++++++++++++++++------------------ > arch/x86/kvm/mmu/mmu_internal.h | 3 + > arch/x86/kvm/mmu/mmutrace.h | 1 + > arch/x86/kvm/mmu/paging_tmpl.h | 63 ++--- > arch/x86/kvm/mmu/tdp_mmu.c | 6 +- > arch/x86/kvm/x86.c | 133 +++------- > 7 files changed, 368 insertions(+), 374 deletions(-) >
The bulk of the changes are to clean up the thorny "unprotect and retry" mess that grew over time. The other notable change is to support yielding in the shadow MMU when zapping rmaps (simply a historic oversight, AFAICT). The following changes since commit 47ac09b91befbb6a235ab620c32af719f8208399: Linux 6.11-rc4 (2024-08-18 13:17:27 -0700) are available in the Git repository at: https://github.com/kvm-x86/linux.git tags/kvm-x86-mmu-6.12 for you to fetch changes up to 9a5bff7f5ec2383e3edac5eda561b52e267ccbb5: KVM: x86/mmu: Use KVM_PAGES_PER_HPAGE() instead of an open coded equivalent (2024-09-09 20:22:08 -0700) ---------------------------------------------------------------- KVM x86 MMU changes for 6.12: - Overhaul the "unprotect and retry" logic to more precisely identify cases where retrying is actually helpful, and to harden all retry paths against putting the guest into an infinite retry loop. - Add support for yielding, e.g. to honor NEED_RESCHED, when zapping rmaps in the shadow MMU. - Refactor pieces of the shadow MMU related to aging SPTEs in prepartion for adding MGLRU support in KVM. - Misc cleanups ---------------------------------------------------------------- Sean Christopherson (33): KVM: x86/mmu: Clean up function comments for dirty logging APIs KVM: x86/mmu: Decrease indentation in logic to sync new indirect shadow page KVM: x86/mmu: Drop pointless "return" wrapper label in FNAME(fetch) KVM: x86/mmu: Reword a misleading comment about checking gpte_changed() KVM: x86/mmu: Replace PFERR_NESTED_GUEST_PAGE with a more descriptive helper KVM: x86/mmu: Trigger unprotect logic only on write-protection page faults KVM: x86/mmu: Skip emulation on page fault iff 1+ SPs were unprotected KVM: x86: Retry to-be-emulated insn in "slow" unprotect path iff sp is zapped KVM: x86: Get RIP from vCPU state when storing it to last_retry_eip KVM: x86: Store gpa as gpa_t, not unsigned long, when unprotecting for retry KVM: x86/mmu: Apply retry protection to "fast nTDP unprotect" path KVM: x86/mmu: Try "unprotect for retry" iff there are indirect SPs KVM: x86: Move EMULTYPE_ALLOW_RETRY_PF to x86_emulate_instruction() KVM: x86: Fold retry_instruction() into x86_emulate_instruction() KVM: x86/mmu: Don't try to unprotect an INVALID_GPA KVM: x86/mmu: Always walk guest PTEs with WRITE access when unprotecting KVM: x86/mmu: Move event re-injection unprotect+retry into common path KVM: x86: Remove manual pfn lookup when retrying #PF after failed emulation KVM: x86: Check EMULTYPE_WRITE_PF_TO_SP before unprotecting gfn KVM: x86: Apply retry protection to "unprotect on failure" path KVM: x86: Update retry protection fields when forcing retry on emulation failure KVM: x86: Rename reexecute_instruction()=>kvm_unprotect_and_retry_on_failure() KVM: x86/mmu: Subsume kvm_mmu_unprotect_page() into the and_retry() version KVM: x86/mmu: Detect if unprotect will do anything based on invalid_list KVM: x86/mmu: WARN on MMIO cache hit when emulating write-protected gfn KVM: x86/mmu: Move walk_slot_rmaps() up near for_each_slot_rmap_range() KVM: x86/mmu: Plumb a @can_yield parameter into __walk_slot_rmaps() KVM: x86/mmu: Add a helper to walk and zap rmaps for a memslot KVM: x86/mmu: Honor NEED_RESCHED when zapping rmaps and blocking is allowed KVM: x86/mmu: Morph kvm_handle_gfn_range() into an aging specific helper KVM: x86/mmu: Fold mmu_spte_age() into kvm_rmap_age_gfn_range() KVM: x86/mmu: Add KVM_RMAP_MANY to replace open coded '1' and '1ul' literals KVM: x86/mmu: Use KVM_PAGES_PER_HPAGE() instead of an open coded equivalent arch/x86/include/asm/kvm_host.h | 14 +- arch/x86/kvm/mmu/mmu.c | 522 ++++++++++++++++++++++------------------ arch/x86/kvm/mmu/mmu_internal.h | 3 + arch/x86/kvm/mmu/mmutrace.h | 1 + arch/x86/kvm/mmu/paging_tmpl.h | 63 ++--- arch/x86/kvm/mmu/tdp_mmu.c | 6 +- arch/x86/kvm/x86.c | 133 +++------- 7 files changed, 368 insertions(+), 374 deletions(-)