[PATCH v3 06/31] KVM: MMU: change kvm_faultin_pfn() arguments to kvm_page_fault

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


Add fields to struct kvm_page_fault corresponding to outputs of
kvm_faultin_pfn(). For now they have to be extracted again from struct
kvm_page_fault in the subsequent steps, but this is temporary until
other functions in the chain are switched over as well.

Suggested-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/mmu.h | 5 ++++
arch/x86/kvm/mmu/mmu.c | 50 ++++++++++++++++------------------
arch/x86/kvm/mmu/paging_tmpl.h | 19 ++++++-------
3 files changed, 36 insertions(+), 38 deletions(-)

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index a5c2d4069964..6697571197a5 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -135,6 +135,11 @@ struct kvm_page_fault {

/* Shifted addr, or result of guest page table walk if addr is a gva. */
gfn_t gfn;
+
+ /* Outputs of kvm_faultin_pfn. */
+ kvm_pfn_t pfn;
+ hva_t hva;
+ bool map_writable;
};

int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault);
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 41dc6796b80b..c2d2d019634b 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3889,11 +3889,9 @@ static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch);
}

-static bool kvm_faultin_pfn(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
- gpa_t cr2_or_gpa, kvm_pfn_t *pfn, hva_t *hva,
- bool write, bool *writable, int *r)
+static bool kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, int *r)
{
- struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
+ struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, fault->gfn);
bool async;

/*
@@ -3907,8 +3905,8 @@ static bool kvm_faultin_pfn(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
if (!kvm_is_visible_memslot(slot)) {
/* Don't expose private memslots to L2. */
if (is_guest_mode(vcpu)) {
- *pfn = KVM_PFN_NOSLOT;
- *writable = false;
+ fault->pfn = KVM_PFN_NOSLOT;
+ fault->map_writable = false;
return false;
}
/*
@@ -3925,23 +3923,25 @@ static bool kvm_faultin_pfn(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
}

async = false;
- *pfn = __gfn_to_pfn_memslot(slot, gfn, false, &async,
- write, writable, hva);
+ fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, &async,
+ fault->write, &fault->map_writable,
+ &fault->hva);
if (!async)
return false; /* *pfn has correct page already */

- if (!prefault && kvm_can_do_async_pf(vcpu)) {
- trace_kvm_try_async_get_page(cr2_or_gpa, gfn);
- if (kvm_find_async_pf_gfn(vcpu, gfn)) {
- trace_kvm_async_pf_doublefault(cr2_or_gpa, gfn);
+ if (!fault->prefault && kvm_can_do_async_pf(vcpu)) {
+ trace_kvm_try_async_get_page(fault->addr, fault->gfn);
+ if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) {
+ trace_kvm_async_pf_doublefault(fault->addr, fault->gfn);
kvm_make_request(KVM_REQ_APF_HALT, vcpu);
goto out_retry;
- } else if (kvm_arch_setup_async_pf(vcpu, cr2_or_gpa, gfn))
+ } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn))
goto out_retry;
}

- *pfn = __gfn_to_pfn_memslot(slot, gfn, false, NULL,
- write, writable, hva);
+ fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, NULL,
+ fault->write, &fault->map_writable,
+ &fault->hva);

out_retry:
*r = RET_PF_RETRY;
@@ -3953,11 +3953,8 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
gpa_t gpa = fault->addr;
u32 error_code = fault->error_code;
bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu);
- bool map_writable;

unsigned long mmu_seq;
- kvm_pfn_t pfn;
- hva_t hva;
int r;

fault->gfn = gpa >> PAGE_SHIFT;
@@ -3975,12 +3972,11 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
mmu_seq = vcpu->kvm->mmu_notifier_seq;
smp_rmb();

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

if (handle_abnormal_pfn(vcpu, fault->is_tdp ? 0 : gpa,
- fault->gfn, pfn, ACC_ALL, &r))
+ fault->gfn, fault->pfn, ACC_ALL, &r))
return r;

r = RET_PF_RETRY;
@@ -3990,25 +3986,25 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
else
write_lock(&vcpu->kvm->mmu_lock);

- if (!is_noslot_pfn(pfn) && mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, hva))
+ if (!is_noslot_pfn(fault->pfn) && mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, fault->hva))
goto out_unlock;
r = make_mmu_pages_available(vcpu);
if (r)
goto out_unlock;

if (is_tdp_mmu_fault)
- r = kvm_tdp_mmu_map(vcpu, gpa, error_code, map_writable, fault->max_level,
- pfn, fault->prefault);
+ r = kvm_tdp_mmu_map(vcpu, gpa, error_code, fault->map_writable, fault->max_level,
+ fault->pfn, fault->prefault);
else
- r = __direct_map(vcpu, gpa, error_code, map_writable, fault->max_level, pfn,
- fault->prefault, fault->is_tdp);
+ r = __direct_map(vcpu, gpa, error_code, fault->map_writable, fault->max_level,
+ fault->pfn, fault->prefault, fault->is_tdp);

out_unlock:
if (is_tdp_mmu_fault)
read_unlock(&vcpu->kvm->mmu_lock);
else
write_unlock(&vcpu->kvm->mmu_lock);
- kvm_release_pfn_clean(pfn);
+ kvm_release_pfn_clean(fault->pfn);
return r;
}

diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 44a19dde5e70..72f0b415be63 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -839,10 +839,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
u32 error_code = fault->error_code;
struct guest_walker walker;
int r;
- kvm_pfn_t pfn;
- hva_t hva;
unsigned long mmu_seq;
- bool map_writable, is_self_change_mapping;
+ bool is_self_change_mapping;

pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code);
WARN_ON_ONCE(fault->is_tdp);
@@ -892,11 +890,10 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
mmu_seq = vcpu->kvm->mmu_notifier_seq;
smp_rmb();

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

- if (handle_abnormal_pfn(vcpu, addr, fault->gfn, pfn, walker.pte_access, &r))
+ if (handle_abnormal_pfn(vcpu, addr, fault->gfn, fault->pfn, walker.pte_access, &r))
return r;

/*
@@ -904,7 +901,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
* we will cache the incorrect access into mmio spte.
*/
if (fault->write && !(walker.pte_access & ACC_WRITE_MASK) &&
- !is_cr0_wp(vcpu->arch.mmu) && !fault->user && !is_noslot_pfn(pfn)) {
+ !is_cr0_wp(vcpu->arch.mmu) && !fault->user && !is_noslot_pfn(fault->pfn)) {
walker.pte_access |= ACC_WRITE_MASK;
walker.pte_access &= ~ACC_USER_MASK;

@@ -920,20 +917,20 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault

r = RET_PF_RETRY;
write_lock(&vcpu->kvm->mmu_lock);
- if (!is_noslot_pfn(pfn) && mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, hva))
+ if (!is_noslot_pfn(fault->pfn) && mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, fault->hva))
goto out_unlock;

kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT);
r = make_mmu_pages_available(vcpu);
if (r)
goto out_unlock;
- r = FNAME(fetch)(vcpu, addr, &walker, error_code, fault->max_level, pfn,
- map_writable, fault->prefault);
+ r = FNAME(fetch)(vcpu, addr, &walker, error_code, fault->max_level, fault->pfn,
+ fault->map_writable, fault->prefault);
kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT);

out_unlock:
write_unlock(&vcpu->kvm->mmu_lock);
- kvm_release_pfn_clean(pfn);
+ kvm_release_pfn_clean(fault->pfn);
return r;
}

--
2.27.0