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| author | Sean Christopherson <seanjc@google.com> | 2021-01-14 16:40:51 -0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-02-04 05:27:17 -0500 |
| commit | c5e2184d1544f9e56140791eff1a351bea2e63b9 (patch) | |
| tree | 66e25896fddf9f472fa38e243ac554b1b4c955a1 /arch/x86/include | |
| parent | 678e90a349a4c22082c1609335ea688f5d4a7139 (diff) | |
| download | linux-c5e2184d1544f9e56140791eff1a351bea2e63b9.tar.gz linux-c5e2184d1544f9e56140791eff1a351bea2e63b9.tar.bz2 linux-c5e2184d1544f9e56140791eff1a351bea2e63b9.zip | |
KVM: x86/mmu: Remove the defunct update_pte() paging hook
Remove the update_pte() shadow paging logic, which was obsoleted by
commit 4731d4c7a077 ("KVM: MMU: out of sync shadow core"), but never
removed. As pointed out by Yu, KVM never write protects leaf page
tables for the purposes of shadow paging, and instead marks their
associated shadow page as unsync so that the guest can write PTEs at
will.
The update_pte() path, which predates the unsync logic, optimizes COW
scenarios by refreshing leaf SPTEs when they are written, as opposed to
zapping the SPTE, restarting the guest, and installing the new SPTE on
the subsequent fault. Since KVM no longer write-protects leaf page
tables, update_pte() is unreachable and can be dropped.
Reported-by: Yu Zhang <yu.c.zhang@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210115004051.4099250-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 3d6616f6f6ef..ed575c5655dd 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -358,8 +358,6 @@ struct kvm_mmu { int (*sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp); void (*invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa); - void (*update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, - u64 *spte, const void *pte); hpa_t root_hpa; gpa_t root_pgd; union kvm_mmu_role mmu_role; @@ -1031,7 +1029,6 @@ struct kvm_arch { struct kvm_vm_stat { ulong mmu_shadow_zapped; ulong mmu_pte_write; - ulong mmu_pte_updated; ulong mmu_pde_zapped; ulong mmu_flooded; ulong mmu_recycled; |