[PATCH v3 03/31] KVM: MMU: change mmu->page_fault() arguments to kvm_page_fault

From: Paolo Bonzini
Date: Fri Sep 24 2021 - 12:32:09 EST


Pass struct kvm_page_fault to mmu->page_fault() instead of
extracting the arguments from the struct. FNAME(page_fault) can use
the precomputed bools from the error code.

Suggested-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 4 ++--
arch/x86/kvm/mmu.h | 7 +++----
arch/x86/kvm/mmu/mmu.c | 15 ++++++++-------
arch/x86/kvm/mmu/paging_tmpl.h | 22 +++++++++++-----------
4 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 0cb35ef26ab3..8e2e79e909e6 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -407,6 +407,7 @@ struct kvm_mmu_root_info {
#define KVM_HAVE_MMU_RWLOCK

struct kvm_mmu_page;
+struct kvm_page_fault;

/*
* x86 supports 4 paging modes (5-level 64-bit, 4-level 64-bit, 3-level 32-bit,
@@ -416,8 +417,7 @@ struct kvm_mmu_page;
struct kvm_mmu {
unsigned long (*get_guest_pgd)(struct kvm_vcpu *vcpu);
u64 (*get_pdptr)(struct kvm_vcpu *vcpu, int index);
- int (*page_fault)(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u32 err,
- bool prefault);
+ int (*page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault);
void (*inject_page_fault)(struct kvm_vcpu *vcpu,
struct x86_exception *fault);
gpa_t (*gva_to_gpa)(struct kvm_vcpu *vcpu, gpa_t gva_or_gpa,
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 0553ef92946e..ee58177bc282 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -131,8 +131,7 @@ struct kvm_page_fault {
const bool is_tdp;
};

-int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
- bool prefault);
+int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault);

static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
u32 err, bool prefault)
@@ -150,9 +149,9 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
};
#ifdef CONFIG_RETPOLINE
if (fault.is_tdp)
- return kvm_tdp_page_fault(vcpu, fault.addr, fault.error_code, fault.prefault);
+ return kvm_tdp_page_fault(vcpu, &fault);
#endif
- return vcpu->arch.mmu->page_fault(vcpu, fault.addr, fault.error_code, fault.prefault);
+ return vcpu->arch.mmu->page_fault(vcpu, &fault);
}

/*
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 376e90f4f413..3ca4b1c69e03 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4012,13 +4012,14 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
return r;
}

-static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa,
- u32 error_code, bool prefault)
+static int nonpaging_page_fault(struct kvm_vcpu *vcpu,
+ struct kvm_page_fault *fault)
{
pgprintk("%s: gva %lx error %x\n", __func__, gpa, error_code);

/* This path builds a PAE pagetable, we can map 2mb pages at maximum. */
- return direct_page_fault(vcpu, gpa, error_code, prefault,
+ return direct_page_fault(vcpu, fault->addr,
+ fault->error_code, fault->prefault,
PG_LEVEL_2M, false);
}

@@ -4055,10 +4056,10 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
}
EXPORT_SYMBOL_GPL(kvm_handle_page_fault);

-int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
- bool prefault)
+int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
{
int max_level;
+ gpa_t gpa = fault->addr;

for (max_level = KVM_MAX_HUGEPAGE_LEVEL;
max_level > PG_LEVEL_4K;
@@ -4070,8 +4071,8 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
break;
}

- return direct_page_fault(vcpu, gpa, error_code, prefault,
- max_level, true);
+ return direct_page_fault(vcpu, gpa, fault->error_code,
+ fault->prefault, max_level, true);
}

static void nonpaging_init_context(struct kvm_mmu *context)
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index b908d2ff6d4c..8eee1200117a 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -833,11 +833,10 @@ FNAME(is_self_change_mapping)(struct kvm_vcpu *vcpu,
* Returns: 1 if we need to emulate the instruction, 0 otherwise, or
* a negative value on error.
*/
-static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code,
- bool prefault)
+static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
{
- bool write_fault = error_code & PFERR_WRITE_MASK;
- bool user_fault = error_code & PFERR_USER_MASK;
+ gpa_t addr = fault->addr;
+ u32 error_code = fault->error_code;
struct guest_walker walker;
int r;
kvm_pfn_t pfn;
@@ -847,6 +846,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code,
int max_level;

pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code);
+ WARN_ON_ONCE(fault->is_tdp);

/*
* If PFEC.RSVD is set, this is a shadow page fault.
@@ -864,7 +864,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code,
*/
if (!r) {
pgprintk("%s: guest page fault\n", __func__);
- if (!prefault)
+ if (!fault->prefault)
kvm_inject_emulated_page_fault(vcpu, &walker.fault);

return RET_PF_RETRY;
@@ -882,7 +882,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code,
vcpu->arch.write_fault_to_shadow_pgtable = false;

is_self_change_mapping = FNAME(is_self_change_mapping)(vcpu,
- &walker, user_fault, &vcpu->arch.write_fault_to_shadow_pgtable);
+ &walker, fault->user, &vcpu->arch.write_fault_to_shadow_pgtable);

if (is_self_change_mapping)
max_level = PG_LEVEL_4K;
@@ -892,8 +892,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code,
mmu_seq = vcpu->kvm->mmu_notifier_seq;
smp_rmb();

- if (kvm_faultin_pfn(vcpu, prefault, walker.gfn, addr, &pfn, &hva,
- write_fault, &map_writable, &r))
+ if (kvm_faultin_pfn(vcpu, fault->prefault, walker.gfn, addr, &pfn, &hva,
+ fault->write, &map_writable, &r))
return r;

if (handle_abnormal_pfn(vcpu, addr, walker.gfn, pfn, walker.pte_access, &r))
@@ -903,8 +903,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code,
* Do not change pte_access if the pfn is a mmio page, otherwise
* we will cache the incorrect access into mmio spte.
*/
- if (write_fault && !(walker.pte_access & ACC_WRITE_MASK) &&
- !is_cr0_wp(vcpu->arch.mmu) && !user_fault && !is_noslot_pfn(pfn)) {
+ if (fault->write && !(walker.pte_access & ACC_WRITE_MASK) &&
+ !is_cr0_wp(vcpu->arch.mmu) && !fault->user && !is_noslot_pfn(pfn)) {
walker.pte_access |= ACC_WRITE_MASK;
walker.pte_access &= ~ACC_USER_MASK;

@@ -928,7 +928,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code,
if (r)
goto out_unlock;
r = FNAME(fetch)(vcpu, addr, &walker, error_code, max_level, pfn,
- map_writable, prefault);
+ map_writable, fault->prefault);
kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT);

out_unlock:
--
2.27.0