Commit b37fbea6 authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Gleb Natapov

KVM: MMU: make return value of mmio page fault handler more readable

Define some meaningful names instead of raw code
Signed-off-by: default avatarXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Reviewed-by: default avatarGleb Natapov <gleb@redhat.com>
Reviewed-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent f2fd125d
......@@ -3224,17 +3224,12 @@ static u64 walk_shadow_page_get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr)
return spte;
}
/*
* If it is a real mmio page fault, return 1 and emulat the instruction
* directly, return 0 to let CPU fault again on the address, -1 is
* returned if bug is detected.
*/
int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct)
{
u64 spte;
if (quickly_check_mmio_pf(vcpu, addr, direct))
return 1;
return RET_MMIO_PF_EMULATE;
spte = walk_shadow_page_get_mmio_spte(vcpu, addr);
......@@ -3247,7 +3242,7 @@ int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct)
trace_handle_mmio_page_fault(addr, gfn, access);
vcpu_cache_mmio_info(vcpu, addr, gfn, access);
return 1;
return RET_MMIO_PF_EMULATE;
}
/*
......@@ -3255,13 +3250,13 @@ int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct)
* it's a BUG if the gfn is not a mmio page.
*/
if (direct && !check_direct_spte_mmio_pf(spte))
return -1;
return RET_MMIO_PF_BUG;
/*
* If the page table is zapped by other cpus, let CPU fault again on
* the address.
*/
return 0;
return RET_MMIO_PF_RETRY;
}
EXPORT_SYMBOL_GPL(handle_mmio_page_fault_common);
......@@ -3271,7 +3266,7 @@ static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr,
int ret;
ret = handle_mmio_page_fault_common(vcpu, addr, direct);
WARN_ON(ret < 0);
WARN_ON(ret == RET_MMIO_PF_BUG);
return ret;
}
......
......@@ -52,6 +52,20 @@
int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4]);
void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask);
/*
* Return values of handle_mmio_page_fault_common:
* RET_MMIO_PF_EMULATE: it is a real mmio page fault, emulate the instruction
* directly.
* RET_MMIO_PF_RETRY: let CPU fault again on the address.
* RET_MMIO_PF_BUG: bug is detected.
*/
enum {
RET_MMIO_PF_EMULATE = 1,
RET_MMIO_PF_RETRY = 0,
RET_MMIO_PF_BUG = -1
};
int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct);
int kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *context);
......
......@@ -5366,10 +5366,10 @@ static int handle_ept_misconfig(struct kvm_vcpu *vcpu)
gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS);
ret = handle_mmio_page_fault_common(vcpu, gpa, true);
if (likely(ret == 1))
if (likely(ret == RET_MMIO_PF_EMULATE))
return x86_emulate_instruction(vcpu, gpa, 0, NULL, 0) ==
EMULATE_DONE;
if (unlikely(!ret))
if (unlikely(ret == RET_MMIO_PF_RETRY))
return 1;
/* It is the real ept misconfig */
......
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