[PATCH v2 22/25] KVM: x86/mmu: replace root_level with cpu_mode.base.level

Paolo Bonzini
2022-02-21T16:24:19Z

Remove another duplicate field of struct kvm_mmu. This time it's
the root level for page table walking; the separate field is
always initialized as cpu_mode.base.level, so its users can look
up the CPU mode directly instead.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/kvm/mmu/mmu.c | 18 +++++++-----------
arch/x86/kvm/mmu/paging_tmpl.h | 4 ++--
3 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 81897aa4e669..ec89b1a488c5 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;
- u8 root_level;
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 c33879f23e94..0c88d4206715 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2130,7 +2130,7 @@ static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterato
iterator->level = vcpu->arch.mmu->root_role.level;

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

@@ -3440,7 +3440,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
* On SVM, reading PDPTRs might access guest memory, which might fault
* and thus might sleep. Grab the PDPTRs before acquiring mmu_lock.
*/
- if (mmu->root_level == PT32E_ROOT_LEVEL) {
+ if (mmu->cpu_mode.base.level == PT32E_ROOT_LEVEL) {
for (i = 0; i < 4; ++i) {
pdptrs[i] = mmu->get_pdptr(vcpu, i);
if (!(pdptrs[i] & PT_PRESENT_MASK))
@@ -3464,7 +3464,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
* Do we shadow a long mode page table? If so we need to
* write-protect the guests page table root.
*/
- if (mmu->root_level >= PT64_ROOT_4LEVEL) {
+ if (mmu->cpu_mode.base.level >= PT64_ROOT_4LEVEL) {
root = mmu_alloc_root(vcpu, root_gfn, 0,
mmu->root_role.level, false);
mmu->root.hpa = root;
@@ -3503,7 +3503,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
for (i = 0; i < 4; ++i) {
WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i]));

- if (mmu->root_level == PT32E_ROOT_LEVEL) {
+ if (mmu->cpu_mode.base.level == PT32E_ROOT_LEVEL) {
if (!(pdptrs[i] & PT_PRESENT_MASK)) {
mmu->pae_root[i] = INVALID_PAE_ROOT;
continue;
@@ -3545,7 +3545,7 @@ 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->root_level >= PT64_ROOT_4LEVEL ||
+ if (mmu->direct_map || mmu->cpu_mode.base.level >= PT64_ROOT_4LEVEL ||
mmu->root_role.level < PT64_ROOT_4LEVEL)
return 0;

@@ -3642,7 +3642,7 @@ void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)

vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY);

- if (vcpu->arch.mmu->root_level >= PT64_ROOT_4LEVEL) {
+ if (vcpu->arch.mmu->cpu_mode.base.level >= PT64_ROOT_4LEVEL) {
hpa_t root = vcpu->arch.mmu->root.hpa;
sp = to_shadow_page(root);

@@ -4348,7 +4348,7 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu,
{
__reset_rsvds_bits_mask(&context->guest_rsvd_check,
vcpu->arch.reserved_gpa_bits,
- context->root_level, is_efer_nx(context),
+ context->cpu_mode.base.level, is_efer_nx(context),
guest_can_use_gbpages(vcpu),
is_cr4_pse(context),
guest_cpuid_is_amd_or_hygon(vcpu));
@@ -4752,7 +4752,6 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, union kvm_mmu_paging_mode cp
context->get_guest_pgd = kvm_get_guest_cr3;
context->get_pdptr = kvm_pdptr_read;
context->inject_page_fault = kvm_inject_page_fault;
- context->root_level = cpu_mode.base.level;

if (!is_cr0_pg(context))
context->gva_to_gpa = nonpaging_gva_to_gpa;
@@ -4782,7 +4781,6 @@ static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *conte
paging64_init_context(context);
else
paging32_init_context(context);
- context->root_level = cpu_mode.base.level;

reset_guest_paging_metadata(vcpu, context);
reset_shadow_zero_bits_mask(vcpu, context);
@@ -4874,7 +4872,6 @@ 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->root_level = level;
context->direct_map = false;
update_permission_bitmask(context, true);
context->pkru_mask = 0;
@@ -4909,7 +4906,6 @@ static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, union kvm_mmu_paging_mode
g_context->get_guest_pgd = kvm_get_guest_cr3;
g_context->get_pdptr = kvm_pdptr_read;
g_context->inject_page_fault = kvm_inject_page_fault;
- g_context->root_level = new_mode.base.level;

/*
* L2 page tables are never shadowed, so there is no need to sync
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 7c0fa115bd56..bdfd38b0f8e6 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -361,7 +361,7 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,

trace_kvm_mmu_pagetable_walk(addr, access);
retry_walk:
- walker->level = mmu->root_level;
+ walker->level = mmu->cpu_mode.base.level;
pte = kvm_mmu_get_guest_pgd(vcpu, mmu);
have_ad = PT_HAVE_ACCESSED_DIRTY(mmu);

@@ -656,7 +656,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault,
WARN_ON_ONCE(gw->gfn != base_gfn);
direct_access = gw->pte_access;

- top_level = vcpu->arch.mmu->root_level;
+ top_level = vcpu->arch.mmu->cpu_mode.base.level;
if (top_level == PT32E_ROOT_LEVEL)
top_level = PT32_ROOT_LEVEL;
/*
--
2.31.1