[PATCH 06/16] KVM: MMU: change page_fault_handle_page_track() arguments to kvm_page_fault

From: Paolo Bonzini
Date: Sat Aug 07 2021 - 09:50:13 EST


Add fields to struct kvm_page_fault corresponding to the arguments
of page_fault_handle_page_track(). The fields are initialized in the
callers, and page_fault_handle_page_track() receives a struct
kvm_page_fault instead of having to extract the arguments out of it.

Suggested-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/mmu.h | 3 +++
arch/x86/kvm/mmu/mmu.c | 18 +++++++++---------
arch/x86/kvm/mmu/paging_tmpl.h | 7 ++++---
3 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 158263847bef..c3d404155ceb 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -132,6 +132,9 @@ struct kvm_page_fault {

/* Input to FNAME(fetch), __direct_map and kvm_tdp_mmu_map. */
u8 max_level;
+
+ /* Shifted addr, or result of guest page table walk if addr is a gva. */
+ gfn_t gfn;
};

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 e93ee0ebe5ff..3af49678d4f8 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3788,20 +3788,19 @@ static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct)
}

static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu,
- u32 error_code, gfn_t gfn)
+ struct kvm_page_fault *fault)
{
- if (unlikely(error_code & PFERR_RSVD_MASK))
+ if (unlikely(fault->rsvd))
return false;

- if (!(error_code & PFERR_PRESENT_MASK) ||
- !(error_code & PFERR_WRITE_MASK))
+ if (!fault->present || !fault->write)
return false;

/*
* guest is writing the page which is write tracked which can
* not be fixed by page fault handler.
*/
- if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE))
+ if (kvm_page_track_is_active(vcpu, fault->gfn, KVM_PAGE_TRACK_WRITE))
return true;

return false;
@@ -3885,13 +3884,13 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu);
bool map_writable;

- gfn_t gfn = gpa >> PAGE_SHIFT;
unsigned long mmu_seq;
kvm_pfn_t pfn;
hva_t hva;
int r;

- if (page_fault_handle_page_track(vcpu, error_code, gfn))
+ fault->gfn = gpa >> PAGE_SHIFT;
+ if (page_fault_handle_page_track(vcpu, fault))
return RET_PF_EMULATE;

r = fast_page_fault(vcpu, gpa, error_code);
@@ -3905,11 +3904,12 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
mmu_seq = vcpu->kvm->mmu_notifier_seq;
smp_rmb();

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

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

r = RET_PF_RETRY;
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 5352323646b0..2ef219bf1745 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -858,7 +858,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
return RET_PF_RETRY;
}

- if (page_fault_handle_page_track(vcpu, error_code, walker.gfn)) {
+ fault->gfn = walker.gfn;
+ if (page_fault_handle_page_track(vcpu, fault)) {
shadow_page_table_clear_flood(vcpu, addr);
return RET_PF_EMULATE;
}
@@ -880,11 +881,11 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
mmu_seq = vcpu->kvm->mmu_notifier_seq;
smp_rmb();

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

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

/*
--
2.27.0