[PATCH 16/23] KVM: MMU: remove extended bits from mmu_role

From: Paolo Bonzini
Date: Fri Feb 04 2022 - 06:58:16 EST

mmu_role represents the role of the root of the page tables.
It does not need any extended bits, as those govern only KVM's
page table walking; the is_* functions used for page table
walking always use the CPU role.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 2 +-
arch/x86/kvm/mmu/mmu.c | 63 ++++++++++++++++-----------------
arch/x86/kvm/mmu/paging_tmpl.h | 2 +-
arch/x86/kvm/mmu/tdp_mmu.c | 2 +-
4 files changed, 34 insertions(+), 35 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 795b345361c8..121eefdb9991 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -433,7 +433,7 @@ struct kvm_mmu {
hpa_t root_hpa;
gpa_t root_pgd;
union kvm_mmu_role cpu_role;
- union kvm_mmu_role mmu_role;
+ union kvm_mmu_page_role mmu_role;
u8 root_level;
u8 shadow_root_level;
bool direct_map;
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 817e6cc916fc..0cb46a74e561 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2045,7 +2045,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
int collisions = 0;
LIST_HEAD(invalid_list);

- role = vcpu->arch.mmu->mmu_role.base;
+ role = vcpu->arch.mmu->mmu_role;
role.level = level;
role.direct = direct;
role.access = access;
@@ -3278,7 +3278,7 @@ void kvm_mmu_free_guest_mode_roots(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu)
* This should not be called while L2 is active, L2 can't invalidate
* _only_ its own roots, e.g. INVVPID unconditionally exits.
*/
- WARN_ON_ONCE(mmu->mmu_role.base.guest_mode);
+ WARN_ON_ONCE(mmu->mmu_role.guest_mode);

for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) {
root_hpa = mmu->prev_roots[i].hpa;
@@ -4146,7 +4146,7 @@ static bool fast_pgd_switch(struct kvm_vcpu *vcpu, gpa_t new_pgd,

void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd)
{
- union kvm_mmu_page_role new_role = vcpu->arch.mmu->mmu_role.base;
+ union kvm_mmu_page_role new_role = vcpu->arch.mmu->mmu_role;
if (!fast_pgd_switch(vcpu, new_pgd, new_role)) {
kvm_mmu_free_roots(vcpu, vcpu->arch.mmu, KVM_MMU_ROOT_CURRENT);
return;
@@ -4696,21 +4696,21 @@ static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu)
return max_tdp_level;
}

-static union kvm_mmu_role
+static union kvm_mmu_page_role
kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu,
union kvm_mmu_role cpu_role)
{
- union kvm_mmu_role role = {0};
+ union kvm_mmu_page_role role = {0};

- role.base.access = ACC_ALL;
- role.base.cr0_wp = true;
- role.base.efer_nx = true;
- role.base.smm = cpu_role.base.smm;
- role.base.guest_mode = cpu_role.base.guest_mode;
- role.base.ad_disabled = (shadow_accessed_mask == 0);
- role.base.level = kvm_mmu_get_tdp_level(vcpu);
- role.base.direct = true;
- role.base.has_4_byte_gpte = false;
+ role.access = ACC_ALL;
+ role.cr0_wp = true;
+ role.efer_nx = true;
+ role.smm = cpu_role.base.smm;
+ role.guest_mode = cpu_role.base.guest_mode;
+ role.ad_disabled = (shadow_accessed_mask == 0);
+ role.level = kvm_mmu_get_tdp_level(vcpu);
+ role.direct = true;
+ role.has_4_byte_gpte = false;

return role;
}
@@ -4720,14 +4720,14 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu,
{
struct kvm_mmu *context = &vcpu->arch.root_mmu;
union kvm_mmu_role cpu_role = kvm_calc_cpu_role(vcpu, regs);
- union kvm_mmu_role mmu_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role);
+ union kvm_mmu_page_role mmu_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role);

if (cpu_role.as_u64 == context->cpu_role.as_u64 &&
- mmu_role.as_u64 == context->mmu_role.as_u64)
+ mmu_role.word == context->mmu_role.word)
return;

context->cpu_role.as_u64 = cpu_role.as_u64;
- context->mmu_role.as_u64 = mmu_role.as_u64;
+ context->mmu_role.word = mmu_role.word;
context->page_fault = kvm_tdp_page_fault;
context->sync_page = nonpaging_sync_page;
context->invlpg = NULL;
@@ -4749,7 +4749,7 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu,
reset_tdp_shadow_zero_bits_mask(context);
}

-static union kvm_mmu_role
+static union kvm_mmu_page_role
kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu,
union kvm_mmu_role role)
{
@@ -4760,19 +4760,19 @@ kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu,
else
role.base.level = PT64_ROOT_4LEVEL;

- return role;
+ return role.base;
}

static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context,
union kvm_mmu_role cpu_role,
- union kvm_mmu_role mmu_role)
+ union kvm_mmu_page_role mmu_role)
{
if (cpu_role.as_u64 == context->cpu_role.as_u64 &&
- mmu_role.as_u64 == context->mmu_role.as_u64)
+ mmu_role.word == context->mmu_role.word)
return;

context->cpu_role.as_u64 = cpu_role.as_u64;
- context->mmu_role.as_u64 = mmu_role.as_u64;
+ context->mmu_role.word = mmu_role.word;

if (!is_cr0_pg(context))
nonpaging_init_context(context);
@@ -4783,7 +4783,7 @@ static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *conte
context->root_level = cpu_role.base.level;

reset_guest_paging_metadata(vcpu, context);
- context->shadow_root_level = mmu_role.base.level;
+ context->shadow_root_level = mmu_role.level;
}

static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu,
@@ -4791,7 +4791,7 @@ static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu,
{
struct kvm_mmu *context = &vcpu->arch.root_mmu;
union kvm_mmu_role cpu_role = kvm_calc_cpu_role(vcpu, regs);
- union kvm_mmu_role mmu_role =
+ union kvm_mmu_page_role mmu_role =
kvm_calc_shadow_mmu_root_page_role(vcpu, cpu_role);

shadow_mmu_init_context(vcpu, context, cpu_role, mmu_role);
@@ -4807,13 +4807,12 @@ static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu,
reset_shadow_zero_bits_mask(vcpu, context, true);
}

-static union kvm_mmu_role
+static union kvm_mmu_page_role
kvm_calc_shadow_npt_root_page_role(struct kvm_vcpu *vcpu,
union kvm_mmu_role role)
{
role.base.level = kvm_mmu_get_tdp_level(vcpu);
-
- return role;
+ return role.base;
}

void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0,
@@ -4826,7 +4825,7 @@ void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0,
.efer = efer,
};
union kvm_mmu_role cpu_role = kvm_calc_cpu_role(vcpu, &regs);
- union kvm_mmu_role mmu_role = kvm_calc_shadow_npt_root_page_role(vcpu, cpu_role);
+ union kvm_mmu_page_role mmu_role = kvm_calc_shadow_npt_root_page_role(vcpu, cpu_role);

shadow_mmu_init_context(vcpu, context, cpu_role, mmu_role);
reset_shadow_zero_bits_mask(vcpu, context, is_efer_nx(context));
@@ -4866,7 +4865,7 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
if (new_role.as_u64 != context->cpu_role.as_u64) {
/* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */
context->cpu_role.as_u64 = new_role.as_u64;
- context->mmu_role.as_u64 = new_role.as_u64;
+ context->mmu_role.word = new_role.base.word;

context->shadow_root_level = level;

@@ -4968,9 +4967,9 @@ void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu)
vcpu->arch.root_mmu.cpu_role.base.level = 0;
vcpu->arch.guest_mmu.cpu_role.base.level = 0;
vcpu->arch.nested_mmu.cpu_role.base.level = 0;
- vcpu->arch.root_mmu.mmu_role.base.level = 0;
- vcpu->arch.guest_mmu.mmu_role.base.level = 0;
- vcpu->arch.nested_mmu.mmu_role.base.level = 0;
+ vcpu->arch.root_mmu.mmu_role.level = 0;
+ vcpu->arch.guest_mmu.mmu_role.level = 0;
+ vcpu->arch.nested_mmu.mmu_role.level = 0;
kvm_mmu_reset_context(vcpu);

/*
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 1b5c7d03f94b..847c4339e4d9 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -1025,7 +1025,7 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
*/
static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
{
- union kvm_mmu_page_role mmu_role = vcpu->arch.mmu->mmu_role.base;
+ union kvm_mmu_page_role mmu_role = vcpu->arch.mmu->mmu_role;
int i;
bool host_writable;
gpa_t first_pte_gpa;
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 8def8f810cb0..dd4c78833016 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -209,7 +209,7 @@ static void tdp_mmu_init_child_sp(struct kvm_mmu_page *child_sp,

hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu)
{
- union kvm_mmu_page_role role = vcpu->arch.mmu->mmu_role.base;
+ union kvm_mmu_page_role role = vcpu->arch.mmu->mmu_role;
struct kvm *kvm = vcpu->kvm;
struct kvm_mmu_page *root;

--
2.31.1