[RFC PATCH 03/10] KVM: x86/mmu: make direct_page_fault() receive single argument

From: Isaku Yamahata
Date: Tue Apr 20 2021 - 06:41:55 EST


Convert direct_page_fault() to receive struct kvm_page_fault instead of
many arguments.

No functional change is intended.

Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
arch/x86/kvm/mmu.h | 10 ++++++++++
arch/x86/kvm/mmu/mmu.c | 32 ++++++++++++++++++++------------
2 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 7fcd9c147e63..fa3b1df502e7 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -112,6 +112,11 @@ struct kvm_page_fault {
gpa_t cr2_or_gpa;
u32 error_code;
bool prefault;
+
+ /* internal state */
+ gfn_t gfn;
+ bool is_tdp;
+ int max_level;
};

static inline void kvm_page_fault_init(
@@ -122,6 +127,11 @@ static inline void kvm_page_fault_init(
kpf->cr2_or_gpa = cr2_or_gpa;
kpf->error_code = error_code;
kpf->prefault = prefault;
+
+ /* default value */
+ kpf->is_tdp = false;
+ kpf->gfn = cr2_or_gpa >> PAGE_SHIFT;
+ kpf->max_level = PG_LEVEL_4K;
}

int kvm_tdp_page_fault(struct kvm_page_fault *kpf);
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 46998cfabfd3..cb90148f90af 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3681,13 +3681,18 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
return false;
}

-static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
- bool prefault, int max_level, bool is_tdp)
-{
+static int direct_page_fault(struct kvm_page_fault *kpf)
+{
+ struct kvm_vcpu *vcpu = kpf->vcpu;
+ gpa_t gpa = kpf->cr2_or_gpa;
+ u32 error_code = kpf->error_code;
+ bool prefault = kpf->prefault;
+ int max_level = kpf->max_level;
+ bool is_tdp = kpf->is_tdp;
bool write = error_code & PFERR_WRITE_MASK;
bool map_writable;

- gfn_t gfn = gpa >> PAGE_SHIFT;
+ gfn_t gfn = kpf->gfn;
unsigned long mmu_seq;
kvm_pfn_t pfn;
hva_t hva;
@@ -3750,10 +3755,12 @@ static int nonpaging_page_fault(struct kvm_page_fault *kpf)
pgprintk("%s: gva %lx error %x\n", __func__,
kpf->cr2_or_gpa, kpf->error_code);

+ kpf->cr2_or_gpa &= PAGE_MASK;
+ kpf->is_tdp = false;
+ kpf->max_level = PG_LEVEL_2M;
+
/* This path builds a PAE pagetable, we can map 2mb pages at maximum. */
- return direct_page_fault(kpf->vcpu, kpf->cr2_or_gpa & PAGE_MASK,
- kpf->error_code,
- kpf->prefault, PG_LEVEL_2M, false);
+ return direct_page_fault(kpf);
}

int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
@@ -3791,21 +3798,22 @@ EXPORT_SYMBOL_GPL(kvm_handle_page_fault);

int kvm_tdp_page_fault(struct kvm_page_fault *kpf)
{
- u32 gpa = kpf->cr2_or_gpa;
+ struct kvm_vcpu *vcpu = kpf->vcpu;
int max_level;
+ kpf->is_tdp = true;

for (max_level = KVM_MAX_HUGEPAGE_LEVEL;
max_level > PG_LEVEL_4K;
max_level--) {
int page_num = KVM_PAGES_PER_HPAGE(max_level);
- gfn_t base = (gpa >> PAGE_SHIFT) & ~(page_num - 1);
+ gfn_t base = kpf->gfn & ~(page_num - 1);

- if (kvm_mtrr_check_gfn_range_consistency(kpf->vcpu, base, page_num))
+ if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num))
break;
}
+ kpf->max_level = max_level;

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

static void nonpaging_init_context(struct kvm_vcpu *vcpu,
--
2.25.1