diff options
author | David Matlack <dmatlack@google.com> | 2022-06-22 15:26:52 -0400 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-06-24 04:51:54 -0400 |
commit | 7f49777550e55a7d6832cbb0873f48f91c175b9c (patch) | |
tree | 0a1dc43e8fc6e3ff344fc22a3117a64e628e170c /arch/x86 | |
parent | 2e65e842c57d72e9a573ba42bc2055b7f626ea1f (diff) |
KVM: x86/mmu: Always pass 0 for @quadrant when gptes are 8 bytes
The quadrant is only used when gptes are 4 bytes, but
mmu_alloc_{direct,shadow}_roots() pass in a non-zero quadrant for PAE
page directories regardless. Make this less confusing by only passing in
a non-zero quadrant when it is actually necessary.
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20220516232138.1783324-6-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index fd1b479bf7fc..f4e7978a6c6a 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3389,9 +3389,10 @@ static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, int quadrant, struct kvm_mmu_page *sp; role.level = level; + role.quadrant = quadrant; - if (role.has_4_byte_gpte) - role.quadrant = quadrant; + WARN_ON_ONCE(quadrant && !role.has_4_byte_gpte); + WARN_ON_ONCE(role.direct && role.has_4_byte_gpte); sp = kvm_mmu_get_page(vcpu, gfn, role); ++sp->root_count; @@ -3427,7 +3428,7 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) for (i = 0; i < 4; ++i) { WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); - root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), i, + root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 0, PT32_ROOT_LEVEL); mmu->pae_root[i] = root | PT_PRESENT_MASK | shadow_me_value; @@ -3512,9 +3513,8 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) struct kvm_mmu *mmu = vcpu->arch.mmu; u64 pdptrs[4], pm_mask; gfn_t root_gfn, root_pgd; + int quadrant, i, r; hpa_t root; - unsigned i; - int r; root_pgd = mmu->get_guest_pgd(vcpu); root_gfn = root_pgd >> PAGE_SHIFT; @@ -3597,7 +3597,15 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) root_gfn = pdptrs[i] >> PAGE_SHIFT; } - root = mmu_alloc_root(vcpu, root_gfn, i, PT32_ROOT_LEVEL); + /* + * If shadowing 32-bit non-PAE page tables, each PAE page + * directory maps one quarter of the guest's non-PAE page + * directory. Othwerise each PAE page direct shadows one guest + * PAE page directory so that quadrant should be 0. + */ + quadrant = (mmu->cpu_role.base.level == PT32_ROOT_LEVEL) ? i : 0; + + root = mmu_alloc_root(vcpu, root_gfn, quadrant, PT32_ROOT_LEVEL); mmu->pae_root[i] = root | pm_mask; } |