[PATCH 6/9] x86/kvm/mmu: make space for source data caching in struct kvm_mmu

Vitaly Kuznetsov
2018-08-02T10:01:29Z

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_role and
extended data. No functional change.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/include/asm/kvm_host.h | 14 +++++++++++++-
arch/x86/kvm/mmu.c | 19 ++++++++++++-------
arch/x86/kvm/vmx.c | 2 +-
3 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c5f116f9783d..830166ab4d59 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -272,6 +272,18 @@ union kvm_mmu_page_role {
};
};

+union kvm_mmu_scache {
+ unsigned int word;
+};
+
+union kvm_mmu_role {
+ unsigned long as_u64;
+ struct {
+ union kvm_mmu_page_role base_role;
+ union kvm_mmu_scache scache;
+ };
+};
+
struct kvm_rmap_head {
unsigned long val;
};
@@ -359,7 +371,7 @@ struct kvm_mmu {
void (*update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
u64 *spte, const void *pte);
hpa_t root_hpa;
- union kvm_mmu_page_role base_role;
+ union kvm_mmu_role mmu_role;
u8 root_level;
u8 shadow_root_level;
u8 ept_ad;
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 85ec027299d6..c538e47e471b 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2331,7 +2331,7 @@ 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;
role.level = level;
role.direct = direct;
if (role.direct)
@@ -4377,7 +4377,8 @@ 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_role.smep_andnot_wp;
struct rsvd_bits_validate *shadow_zero_check;
int i;

@@ -4696,7 +4697,7 @@ 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_role.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;
@@ -4777,7 +4778,7 @@ 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_role.word = mmu_base_role_mask.word &
kvm_calc_shadow_mmu_root_page_role(vcpu).word;
reset_shadow_zero_bits_mask(vcpu, context);
}
@@ -4786,7 +4787,7 @@ EXPORT_SYMBOL_GPL(kvm_init_shadow_mmu);
static union kvm_mmu_page_role
kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty)
{
- union kvm_mmu_page_role role = vcpu->arch.mmu->base_role;
+ union kvm_mmu_page_role role = vcpu->arch.mmu->mmu_role.base_role;

role.level = PT64_ROOT_4LEVEL;
role.direct = false;
@@ -4816,7 +4817,8 @@ 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_role.word =
+ root_page_role.word & mmu_base_role_mask.word;
context->get_pdptr = kvm_pdptr_read;

update_permission_bitmask(vcpu, context, true);
@@ -5131,10 +5133,13 @@ static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,

local_flush = true;
while (npte--) {
+ unsigned int base_role =
+ vcpu->arch.mmu->mmu_role.base_role.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))
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 494148818b8d..0d41116bef1f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -9028,7 +9028,7 @@ 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_role.ad_disabled = !accessed_dirty;
vmcs12->ept_pointer = address;
/*
* TODO: Check what's the correct approach in case
--
2.14.4