From fce92dce79dbf5fff39c7ac2fb149729d79b7a39 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Tue, 12 Jul 2011 03:28:54 +0800 Subject: [PATCH] KVM: MMU: filter out the mmio pfn from the fault pfn If the page fault is caused by mmio, the gfn can not be found in memslots, and 'bad_pfn' is returned on gfn_to_hva path, so we can use 'bad_pfn' to identify the mmio page fault. And, to clarify the meaning of mmio pfn, we return fault page instead of bad page when the gfn is not allowd to prefetch Signed-off-by: Xiao Guangrong Signed-off-by: Avi Kivity --- arch/x86/kvm/mmu.c | 4 ++-- include/linux/kvm_host.h | 5 +++++ virt/kvm/kvm_main.c | 16 ++++++++++++++-- 3 files changed, 21 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 5334b4e9ecc7..96a7ed4e6837 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2085,8 +2085,8 @@ static pfn_t pte_prefetch_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn, slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, no_dirty_log); if (!slot) { - get_page(bad_page); - return page_to_pfn(bad_page); + get_page(fault_page); + return page_to_pfn(fault_page); } hva = gfn_to_hva_memslot(slot, gfn); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index c8e023902f79..eabb21a30c34 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -327,12 +327,17 @@ static inline struct kvm_memslots *kvm_memslots(struct kvm *kvm) static inline int is_error_hpa(hpa_t hpa) { return hpa >> HPA_MSB; } extern struct page *bad_page; +extern struct page *fault_page; + extern pfn_t bad_pfn; +extern pfn_t fault_pfn; int is_error_page(struct page *page); int is_error_pfn(pfn_t pfn); int is_hwpoison_pfn(pfn_t pfn); int is_fault_pfn(pfn_t pfn); +int is_noslot_pfn(pfn_t pfn); +int is_invalid_pfn(pfn_t pfn); int kvm_is_error_hva(unsigned long addr); int kvm_set_memory_region(struct kvm *kvm, struct kvm_userspace_memory_region *mem, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d5ef9ebcaff7..56f3c704fd74 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -101,8 +101,8 @@ static bool largepages_enabled = true; static struct page *hwpoison_page; static pfn_t hwpoison_pfn; -static struct page *fault_page; -static pfn_t fault_pfn; +struct page *fault_page; +pfn_t fault_pfn; inline int kvm_is_mmio_pfn(pfn_t pfn) { @@ -931,6 +931,18 @@ int is_fault_pfn(pfn_t pfn) } EXPORT_SYMBOL_GPL(is_fault_pfn); +int is_noslot_pfn(pfn_t pfn) +{ + return pfn == bad_pfn; +} +EXPORT_SYMBOL_GPL(is_noslot_pfn); + +int is_invalid_pfn(pfn_t pfn) +{ + return pfn == hwpoison_pfn || pfn == fault_pfn; +} +EXPORT_SYMBOL_GPL(is_invalid_pfn); + static inline unsigned long bad_hva(void) { return PAGE_OFFSET; -- 2.34.1