[PATCH 22/22] KVM: x86/mmu: replace direct_map with root_role.direct

From: Paolo Bonzini
Date: Thu Apr 14 2022 - 03:42:22 EST


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_role.base.direct

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

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

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
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 3e3fcffe1b88..2c20f715f009 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -436,7 +436,6 @@ struct kvm_mmu {
struct kvm_mmu_root_info root;
union kvm_cpu_role cpu_role;
union kvm_mmu_page_role root_role;
- bool direct_map;

/*
* The pkru_mask indicates if protection key checks are needed. It
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 507fcf3a5080..69a30d6d1e2b 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2028,7 +2028,7 @@ 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;
@@ -2133,7 +2133,7 @@ static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterato

if (iterator->level >= PT64_ROOT_4LEVEL &&
vcpu->arch.mmu->cpu_role.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) {
@@ -2515,7 +2515,7 @@ 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);
@@ -3553,7 +3553,8 @@ 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_role.base.level >= PT64_ROOT_4LEVEL ||
+ if (mmu->root_role.direct ||
+ mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL ||
mmu->root_role.level < PT64_ROOT_4LEVEL)
return 0;

@@ -3650,7 +3651,7 @@ 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))
@@ -3880,7 +3881,7 @@ static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,

arch.token = alloc_apf_token(vcpu);
arch.gfn = gfn;
- arch.direct_map = vcpu->arch.mmu->direct_map;
+ arch.direct_map = vcpu->arch.mmu->root_role.direct;
arch.cr3 = vcpu->arch.mmu->get_guest_pgd(vcpu);

return kvm_setup_async_pf(vcpu, cr2_or_gpa,
@@ -4098,7 +4099,6 @@ 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,
@@ -4680,7 +4680,6 @@ 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)
@@ -4689,7 +4688,6 @@ 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_cpu_role
@@ -4778,7 +4776,6 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu,
context->page_fault = kvm_tdp_page_fault;
context->sync_page = nonpaging_sync_page;
context->invlpg = NULL;
- context->direct_map = true;
context->get_guest_pgd = get_cr3;
context->get_pdptr = kvm_pdptr_read;
context->inject_page_fault = kvm_inject_page_fault;
@@ -4907,7 +4904,7 @@ 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);
@@ -5023,13 +5020,13 @@ 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);
@@ -5286,7 +5283,7 @@ 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;
@@ -5317,7 +5314,7 @@ 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 9866853ca320..ab336f7c82e4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8101,7 +8101,7 @@ 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.
@@ -8134,7 +8134,7 @@ 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);
@@ -8202,7 +8202,7 @@ 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));
@@ -8482,7 +8482,7 @@ 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;
}
@@ -12360,7 +12360,7 @@ 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;

@@ -12368,7 +12368,7 @@ 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 != vcpu->arch.mmu->get_guest_pgd(vcpu))
return;

--
2.31.1