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 <xiaoguangr...@cn.fujitsu.com> --- 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 5334b4e..96a7ed4 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 31ebb59..3e548e8 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -326,12 +326,17 @@ 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_mmio_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 11d2783..c7d41d4 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_mmio_pfn(pfn_t pfn) +{ + return pfn == bad_pfn; +} +EXPORT_SYMBOL_GPL(is_mmio_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; -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html