[PATCH v4 04/11] KVM: x86/mmu: Handle error PFNs in kvm_faultin_pfn()

Sean Christopherson
2022-10-12T18:17:47Z

From: David Matlack <dmatlack@google.com>

Handle error PFNs in kvm_faultin_pfn() rather than relying on the caller
to invoke handle_abnormal_pfn() after kvm_faultin_pfn().
Opportunistically rename kvm_handle_bad_page() to kvm_handle_error_pfn()
to make it more consistent with is_error_pfn().

This commit moves KVM closer to being able to drop
handle_abnormal_pfn(), which will reduce the amount of duplicate code in
the various page fault handlers.

No functional change intended.

Signed-off-by: David Matlack <dmatlack@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/mmu/mmu.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 72c3dc1884f6..6417a909181c 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3155,7 +3155,7 @@ static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *
send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, PAGE_SHIFT, tsk);
}

-static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn)
+static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn)
{
/*
* Do not cache the mmio info caused by writing the readonly gfn
@@ -3176,10 +3176,6 @@ static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn)
static int handle_abnormal_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault,
unsigned int access)
{
- /* The pfn is invalid, report the error! */
- if (unlikely(is_error_pfn(fault->pfn)))
- return kvm_handle_bad_page(vcpu, fault->gfn, fault->pfn);
-
if (unlikely(!fault->slot)) {
gva_t gva = fault->is_tdp ? 0 : fault->addr;

@@ -4201,10 +4197,19 @@ static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault

static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
{
+ int ret;
+
fault->mmu_seq = vcpu->kvm->mmu_invalidate_seq;
smp_rmb();

- return __kvm_faultin_pfn(vcpu, fault);
+ ret = __kvm_faultin_pfn(vcpu, fault);
+ if (ret != RET_PF_CONTINUE)
+ return ret;
+
+ if (unlikely(is_error_pfn(fault->pfn)))
+ return kvm_handle_error_pfn(vcpu, fault->gfn, fault->pfn);
+
+ return RET_PF_CONTINUE;
}

/*