UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

KVM: x86/mmu: Avoid indirect call for get_cr3 

Most of the time, calls to get_guest_pgd result in calling
kvm_read_cr3 (the exception is only nested TDP).  Hardcode
the default instead of using the get_cr3 function, avoiding
a retpoline if they are enabled.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathias Krause <minipli@grsecurity.net>
Link: https://lore.kernel.org/r/20230322013731.102955-2-minipli@grsecurity.net
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Paolo Bonzini 2023-03-22 02:37:26 +01:00 committed by Sean Christopherson
parent f3d90f901d
commit 2fdcc1b324
2 changed files with 21 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
arch/x86/kvm/mmu/mmu.c
View File

@ -256,6 +256,20 @@ static struct kvm_mmu_role_regs vcpu_to_role_regs(struct kvm_vcpu *vcpu)
return regs;
}
static unsigned long get_guest_cr3(struct kvm_vcpu *vcpu)
{
return kvm_read_cr3(vcpu);
}
static inline unsigned long kvm_mmu_get_guest_pgd(struct kvm_vcpu *vcpu,
struct kvm_mmu *mmu)
{
if (IS_ENABLED(CONFIG_RETPOLINE) && mmu->get_guest_pgd == get_guest_cr3)
return kvm_read_cr3(vcpu);
return mmu->get_guest_pgd(vcpu);
}
static inline bool kvm_available_flush_tlb_with_range(void)
{
return kvm_x86_ops.tlb_remote_flush_with_range;
@ -3801,7 +3815,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
int quadrant, i, r;
hpa_t root;
root_pgd = mmu->get_guest_pgd(vcpu);
root_pgd = kvm_mmu_get_guest_pgd(vcpu, mmu);
root_gfn = root_pgd >> PAGE_SHIFT;
if (mmu_check_root(vcpu, root_gfn))
@ -4251,7 +4265,7 @@ 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->root_role.direct;
arch.cr3 = vcpu->arch.mmu->get_guest_pgd(vcpu);
arch.cr3 = kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu);
return kvm_setup_async_pf(vcpu, cr2_or_gpa,
kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch);
@ -4270,7 +4284,7 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
return;
if (!vcpu->arch.mmu->root_role.direct &&
work->arch.cr3 != vcpu->arch.mmu->get_guest_pgd(vcpu))
work->arch.cr3 != kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu))
return;
kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true, NULL);
@ -4673,11 +4687,6 @@ void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd)
}
EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd);
static unsigned long get_cr3(struct kvm_vcpu *vcpu)
{
return kvm_read_cr3(vcpu);
}
static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn,
unsigned int access)
{
@ -5223,7 +5232,7 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu,
context->root_role.word = root_role.word;
context->page_fault = kvm_tdp_page_fault;
context->sync_spte = NULL;
context->get_guest_pgd = get_cr3;
context->get_guest_pgd = get_guest_cr3;
context->get_pdptr = kvm_pdptr_read;
context->inject_page_fault = kvm_inject_page_fault;
@ -5372,7 +5381,7 @@ static void init_kvm_softmmu(struct kvm_vcpu *vcpu,
kvm_init_shadow_mmu(vcpu, cpu_role);
context->get_guest_pgd = get_cr3;
context->get_guest_pgd = get_guest_cr3;
context->get_pdptr = kvm_pdptr_read;
context->inject_page_fault = kvm_inject_page_fault;
}
@ -5386,7 +5395,7 @@ static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu,
return;
g_context->cpu_role.as_u64 = new_mode.as_u64;
g_context->get_guest_pgd = get_cr3;
g_context->get_guest_pgd = get_guest_cr3;
g_context->get_pdptr = kvm_pdptr_read;
g_context->inject_page_fault = kvm_inject_page_fault;

2
arch/x86/kvm/mmu/paging_tmpl.h
View File

@ -324,7 +324,7 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
trace_kvm_mmu_pagetable_walk(addr, access);
retry_walk:
walker->level = mmu->cpu_role.base.level;
pte = mmu->get_guest_pgd(vcpu);
pte = kvm_mmu_get_guest_pgd(vcpu, mmu);
have_ad = PT_HAVE_ACCESSED_DIRTY(mmu);
#if PTTYPE == 64