Introduce gfn_to_page_atomic() and gfn_to_pfn_atomic(), those functions is fast path and can used in atomic context, the later patch will use those
Signed-off-by: Xiao Guangrong <[email protected]> --- arch/x86/mm/gup.c | 2 + include/linux/kvm_host.h | 2 + virt/kvm/kvm_main.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 54 insertions(+), 0 deletions(-) diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c index 738e659..0c9034b 100644 --- a/arch/x86/mm/gup.c +++ b/arch/x86/mm/gup.c @@ -6,6 +6,7 @@ */ #include <linux/sched.h> #include <linux/mm.h> +#include <linux/module.h> #include <linux/vmstat.h> #include <linux/highmem.h> @@ -274,6 +275,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, return nr; } +EXPORT_SYMBOL_GPL(__get_user_pages_fast); /** * get_user_pages_fast() - pin user pages in memory diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 2d96555..98c3e00 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -289,6 +289,7 @@ void kvm_arch_flush_shadow(struct kvm *kvm); gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn); gfn_t unalias_gfn_instantiation(struct kvm *kvm, gfn_t gfn); +struct page *gfn_to_page_atomic(struct kvm *kvm, gfn_t gfn); struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn); unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn); void kvm_release_page_clean(struct page *page); @@ -296,6 +297,7 @@ void kvm_release_page_dirty(struct page *page); void kvm_set_page_dirty(struct page *page); void kvm_set_page_accessed(struct page *page); +pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn); pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn); pfn_t gfn_to_pfn_memslot(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 84a0906..b806f29 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -942,6 +942,41 @@ unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn) } EXPORT_SYMBOL_GPL(gfn_to_hva); +static pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr) +{ + struct page *page[1]; + int npages; + pfn_t pfn; + + npages = __get_user_pages_fast(addr, 1, 1, page); + + if (unlikely(npages != 1)) { + if (is_hwpoison_address(addr)) { + get_page(hwpoison_page); + return page_to_pfn(hwpoison_page); + } + get_page(bad_page); + return page_to_pfn(bad_page); + } else + pfn = page_to_pfn(page[0]); + + return pfn; +} + +pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn) +{ + unsigned long addr; + + addr = gfn_to_hva(kvm, gfn); + if (kvm_is_error_hva(addr)) { + get_page(bad_page); + return page_to_pfn(bad_page); + } + + return hva_to_pfn_atomic(kvm, addr); +} +EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic); + static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr) { struct page *page[1]; @@ -1000,6 +1035,21 @@ pfn_t gfn_to_pfn_memslot(struct kvm *kvm, return hva_to_pfn(kvm, addr); } +struct page *gfn_to_page_atomic(struct kvm *kvm, gfn_t gfn) +{ + pfn_t pfn; + + pfn = gfn_to_pfn_atomic(kvm, gfn); + if (!kvm_is_mmio_pfn(pfn)) + return pfn_to_page(pfn); + + WARN_ON(kvm_is_mmio_pfn(pfn)); + + get_page(bad_page); + return bad_page; +} +EXPORT_SYMBOL_GPL(gfn_to_page_atomic); + struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn) { pfn_t pfn; -- 1.6.1.2 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
