diff options
| author | Lai Jiangshan <laijs@linux.alibaba.com> | 2021-09-18 08:56:35 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-09-30 04:27:10 -0400 |
| commit | f1c4a88c41ea04a7036409a37e17cf22a8dbe9e2 (patch) | |
| tree | f7cd60369fdc058d0310868dda8932fdacdd7401 | |
| parent | cc2a8e66bbcd4b55e9012cb0447e9386dcb6367e (diff) | |
| download | linux-f1c4a88c41ea04a7036409a37e17cf22a8dbe9e2.tar.bz2 | |
KVM: X86: Don't unsync pagetables when speculative
We'd better only unsync the pagetable when there just was a really
write fault on a level-1 pagetable.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210918005636.3675-10-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 6 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/mmu_internal.h | 3 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/spte.c | 2 |
3 files changed, 8 insertions, 3 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index ccfcdc02d214..73aa15e89311 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -2582,7 +2582,8 @@ static void kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must * be write-protected. */ -int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn, bool can_unsync) +int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn, bool can_unsync, + bool speculative) { struct kvm_mmu_page *sp; bool locked = false; @@ -2608,6 +2609,9 @@ int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn, bool can_unsync) if (sp->unsync) continue; + if (speculative) + return -EEXIST; + /* * TDP MMU page faults require an additional spinlock as they * run with mmu_lock held for read, not write, and the unsync diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h index bf2bdbf333c2..2ba12ef46cb0 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -124,7 +124,8 @@ static inline bool is_nx_huge_page_enabled(void) return READ_ONCE(nx_huge_pages); } -int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn, bool can_unsync); +int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn, bool can_unsync, + bool speculative); void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn); void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn); diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c index 3e97cdb13eb7..b68a580f3510 100644 --- a/arch/x86/kvm/mmu/spte.c +++ b/arch/x86/kvm/mmu/spte.c @@ -159,7 +159,7 @@ int make_spte(struct kvm_vcpu *vcpu, unsigned int pte_access, int level, * e.g. it's write-tracked (upper-level SPs) or has one or more * shadow pages and unsync'ing pages is not allowed. */ - if (mmu_try_to_unsync_pages(vcpu, gfn, can_unsync)) { + if (mmu_try_to_unsync_pages(vcpu, gfn, can_unsync, speculative)) { pgprintk("%s: found shadow page for %llx, marking ro\n", __func__, gfn); ret |= SET_SPTE_WRITE_PROTECTED_PT; |