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authorVitaly Kuznetsov <vkuznets@redhat.com>2018-10-08 21:28:10 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2018-10-17 00:30:05 +0200
commit36d9594dfbf22a59adb986d85e0543886ab898f2 (patch)
tree711eb9c84799dfffc805f695b067550f69de69a2 /arch/x86/kvm
parentx86/kvm/mmu: get rid of redundant kvm_mmu_setup() (diff)
downloadlinux-dev-36d9594dfbf22a59adb986d85e0543886ab898f2.tar.xz
linux-dev-36d9594dfbf22a59adb986d85e0543886ab898f2.zip
x86/kvm/mmu: make space for source data caching in struct kvm_mmu
In preparation to MMU reconfiguration avoidance we need a space to cache source data. As this partially intersects with kvm_mmu_page_role, create 64bit sized union kvm_mmu_role holding both base and extended data. No functional change. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r--arch/x86/kvm/mmu.c26
-rw-r--r--arch/x86/kvm/vmx.c2
2 files changed, 21 insertions, 7 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index dd147fa5b3f4..3301973527aa 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2375,7 +2375,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
int collisions = 0;
LIST_HEAD(invalid_list);
- role = vcpu->arch.mmu->base_role;
+ role = vcpu->arch.mmu->mmu_role.base;
role.level = level;
role.direct = direct;
if (role.direct)
@@ -4423,7 +4423,8 @@ static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu,
void
reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context)
{
- bool uses_nx = context->nx || context->base_role.smep_andnot_wp;
+ bool uses_nx = context->nx ||
+ context->mmu_role.base.smep_andnot_wp;
struct rsvd_bits_validate *shadow_zero_check;
int i;
@@ -4742,7 +4743,7 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
{
struct kvm_mmu *context = vcpu->arch.mmu;
- context->base_role.word = mmu_base_role_mask.word &
+ context->mmu_role.base.word = mmu_base_role_mask.word &
kvm_calc_tdp_mmu_root_page_role(vcpu).word;
context->page_fault = tdp_page_fault;
context->sync_page = nonpaging_sync_page;
@@ -4823,7 +4824,7 @@ void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu)
else
paging32_init_context(vcpu, context);
- context->base_role.word = mmu_base_role_mask.word &
+ context->mmu_role.base.word = mmu_base_role_mask.word &
kvm_calc_shadow_mmu_root_page_role(vcpu).word;
reset_shadow_zero_bits_mask(vcpu, context);
}
@@ -4865,7 +4866,8 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
context->update_pte = ept_update_pte;
context->root_level = PT64_ROOT_4LEVEL;
context->direct_map = false;
- context->base_role.word = root_page_role.word & mmu_base_role_mask.word;
+ context->mmu_role.base.word =
+ root_page_role.word & mmu_base_role_mask.word;
update_permission_bitmask(vcpu, context, true);
update_pkru_bitmask(vcpu, context, true);
@@ -5179,10 +5181,12 @@ static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
local_flush = true;
while (npte--) {
+ u32 base_role = vcpu->arch.mmu->mmu_role.base.word;
+
entry = *spte;
mmu_page_zap_pte(vcpu->kvm, sp, spte);
if (gentry &&
- !((sp->role.word ^ vcpu->arch.mmu->base_role.word)
+ !((sp->role.word ^ base_role)
& mmu_base_role_mask.word) && rmap_can_add(vcpu))
mmu_pte_write_new_pte(vcpu, sp, spte, &gentry);
if (need_remote_flush(entry, *spte))
@@ -5879,6 +5883,16 @@ int kvm_mmu_module_init(void)
{
int ret = -ENOMEM;
+ /*
+ * MMU roles use union aliasing which is, generally speaking, an
+ * undefined behavior. However, we supposedly know how compilers behave
+ * and the current status quo is unlikely to change. Guardians below are
+ * supposed to let us know if the assumption becomes false.
+ */
+ BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32));
+ BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32));
+ BUILD_BUG_ON(sizeof(union kvm_mmu_role) != sizeof(u64));
+
kvm_mmu_reset_all_pte_masks();
pte_list_desc_cache = kmem_cache_create("pte_list_desc",
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 02888031d038..6f44d3a63434 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -9263,7 +9263,7 @@ static int nested_vmx_eptp_switching(struct kvm_vcpu *vcpu,
kvm_mmu_unload(vcpu);
mmu->ept_ad = accessed_dirty;
- mmu->base_role.ad_disabled = !accessed_dirty;
+ mmu->mmu_role.base.ad_disabled = !accessed_dirty;
vmcs12->ept_pointer = address;
/*
* TODO: Check what's the correct approach in case