[PATCH v2 23/25] KVM: x86/mmu: replace direct_map with root_role.direct

Paolo Bonzini
2022-02-21T16:23:41Z

direct_map is always equal to the direct field of the root page's role:

- for shadow paging, direct_map is true if CR0.PG=0 and root_role.direct is
copied from cpu_mode.base.direct

- for TDP, it is always true and root_role.direct is also always true

- for shadow EPT, it is always false and root_role.direct is also always
false

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/kvm/mmu/mmu.c | 27 ++++++++++++---------------
arch/x86/kvm/x86.c | 12 ++++++------
3 files changed, 18 insertions(+), 22 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ec89b1a488c5..af90d0653139 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -431,7 +431,6 @@ struct kvm_mmu {
struct kvm_mmu_root_info root;
union kvm_mmu_paging_mode cpu_mode;
union kvm_mmu_page_role root_role;
- bool direct_map;
struct kvm_mmu_root_info prev_roots[KVM_MMU_NUM_PREV_ROOTS];

/*
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 0c88d4206715..8eb2c0373309 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2029,7 +2029,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
int direct,
unsigned int access)
{
- bool direct_mmu = vcpu->arch.mmu->direct_map;
+ bool direct_mmu = vcpu->arch.mmu->root_role.direct;
union kvm_mmu_page_role role;
struct hlist_head *sp_list;
unsigned quadrant;
@@ -2131,7 +2131,7 @@ static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterato

if (iterator->level >= PT64_ROOT_4LEVEL &&
vcpu->arch.mmu->cpu_mode.base.level < PT64_ROOT_4LEVEL &&
- !vcpu->arch.mmu->direct_map)
+ !vcpu->arch.mmu->root_role.direct)
iterator->level = PT32E_ROOT_LEVEL;

if (iterator->level == PT32E_ROOT_LEVEL) {
@@ -2507,7 +2507,7 @@ static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
gpa_t gpa;
int r;

- if (vcpu->arch.mmu->direct_map)
+ if (vcpu->arch.mmu->root_role.direct)
return 0;

gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL);
@@ -3545,7 +3545,8 @@ static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu)
* equivalent level in the guest's NPT to shadow. Allocate the tables
* on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare.
*/
- if (mmu->direct_map || mmu->cpu_mode.base.level >= PT64_ROOT_4LEVEL ||
+ if (mmu->root_role.direct ||
+ mmu->cpu_mode.base.level >= PT64_ROOT_4LEVEL ||
mmu->root_role.level < PT64_ROOT_4LEVEL)
return 0;

@@ -3634,7 +3635,7 @@ void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
int i;
struct kvm_mmu_page *sp;

- if (vcpu->arch.mmu->direct_map)
+ if (vcpu->arch.mmu->root_role.direct)
return;

if (!VALID_PAGE(vcpu->arch.mmu->root.hpa))
@@ -3854,7 +3855,7 @@ static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,

arch.token = (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id;
arch.gfn = gfn;
- arch.direct_map = mmu->direct_map;
+ arch.direct_map = mmu->root_role.direct;
arch.cr3 = kvm_mmu_get_guest_pgd(vcpu, mmu);

return kvm_setup_async_pf(vcpu, cr2_or_gpa,
@@ -4072,7 +4073,6 @@ static void nonpaging_init_context(struct kvm_mmu *context)
context->gva_to_gpa = nonpaging_gva_to_gpa;
context->sync_page = nonpaging_sync_page;
context->invlpg = NULL;
- context->direct_map = true;
}

static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd,
@@ -4654,7 +4654,6 @@ static void paging64_init_context(struct kvm_mmu *context)
context->gva_to_gpa = paging64_gva_to_gpa;
context->sync_page = paging64_sync_page;
context->invlpg = paging64_invlpg;
- context->direct_map = false;
}

static void paging32_init_context(struct kvm_mmu *context)
@@ -4663,7 +4662,6 @@ static void paging32_init_context(struct kvm_mmu *context)
context->gva_to_gpa = paging32_gva_to_gpa;
context->sync_page = paging32_sync_page;
context->invlpg = paging32_invlpg;
- context->direct_map = false;
}

static union kvm_mmu_paging_mode
@@ -4748,7 +4746,6 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, union kvm_mmu_paging_mode cp
context->page_fault = kvm_tdp_page_fault;
context->sync_page = nonpaging_sync_page;
context->invlpg = NULL;
- context->direct_map = true;
context->get_guest_pgd = kvm_get_guest_cr3;
context->get_pdptr = kvm_pdptr_read;
context->inject_page_fault = kvm_inject_page_fault;
@@ -4872,7 +4869,7 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
context->gva_to_gpa = ept_gva_to_gpa;
context->sync_page = ept_sync_page;
context->invlpg = ept_invlpg;
- context->direct_map = false;
+
update_permission_bitmask(context, true);
context->pkru_mask = 0;
reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level);
@@ -4987,13 +4984,13 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
{
int r;

- r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->direct_map);
+ r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->root_role.direct);
if (r)
goto out;
r = mmu_alloc_special_roots(vcpu);
if (r)
goto out;
- if (vcpu->arch.mmu->direct_map)
+ if (vcpu->arch.mmu->root_role.direct)
r = mmu_alloc_direct_roots(vcpu);
else
r = mmu_alloc_shadow_roots(vcpu);
@@ -5197,7 +5194,7 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code,
void *insn, int insn_len)
{
int r, emulation_type = EMULTYPE_PF;
- bool direct = vcpu->arch.mmu->direct_map;
+ bool direct = vcpu->arch.mmu->root_role.direct;

if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root.hpa)))
return RET_PF_RETRY;
@@ -5228,7 +5225,7 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code,
* paging in both guests. If true, we simply unprotect the page
* and resume the guest.
*/
- if (vcpu->arch.mmu->direct_map &&
+ if (vcpu->arch.mmu->root_role.direct &&
(error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) {
kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa));
return 1;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1546a25a9307..53730e81ceb5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8016,7 +8016,7 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
WARN_ON_ONCE(!(emulation_type & EMULTYPE_PF)))
return false;

- if (!vcpu->arch.mmu->direct_map) {
+ if (!vcpu->arch.mmu->root_role.direct) {
/*
* Write permission should be allowed since only
* write access need to be emulated.
@@ -8049,7 +8049,7 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
kvm_release_pfn_clean(pfn);

/* The instructions are well-emulated on direct mmu. */
- if (vcpu->arch.mmu->direct_map) {
+ if (vcpu->arch.mmu->root_role.direct) {
unsigned int indirect_shadow_pages;

write_lock(&vcpu->kvm->mmu_lock);
@@ -8117,7 +8117,7 @@ static bool retry_instruction(struct x86_emulate_ctxt *ctxt,
vcpu->arch.last_retry_eip = ctxt->eip;
vcpu->arch.last_retry_addr = cr2_or_gpa;

- if (!vcpu->arch.mmu->direct_map)
+ if (!vcpu->arch.mmu->root_role.direct)
gpa = kvm_mmu_gva_to_gpa_write(vcpu, cr2_or_gpa, NULL);

kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(gpa));
@@ -8397,7 +8397,7 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
ctxt->exception.address = cr2_or_gpa;

/* With shadow page tables, cr2 contains a GVA or nGPA. */
- if (vcpu->arch.mmu->direct_map) {
+ if (vcpu->arch.mmu->root_role.direct) {
ctxt->gpa_available = true;
ctxt->gpa_val = cr2_or_gpa;
}
@@ -12198,7 +12198,7 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
{
int r;

- if ((vcpu->arch.mmu->direct_map != work->arch.direct_map) ||
+ if ((vcpu->arch.mmu->root_role.direct != work->arch.direct_map) ||
work->wakeup_all)
return;

@@ -12206,7 +12206,7 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
if (unlikely(r))
return;

- if (!vcpu->arch.mmu->direct_map &&
+ if (!vcpu->arch.mmu->root_role.direct &&
work->arch.cr3 != kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu))
return;

--
2.31.1