From f42e289a2095f61755e6ca5fd1370d441bf589d5 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 10 Oct 2024 11:24:18 -0700 Subject: KVM: Add support for read-only usage of gfn_to_page() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Rework gfn_to_page() to support read-only accesses so that it can be used by arm64 to get MTE tags out of guest memory. Opportunistically rewrite the comment to be even more stern about using gfn_to_page(), as there are very few scenarios where requiring a struct page is actually the right thing to do (though there are such scenarios). Add a FIXME to call out that KVM probably should be pinning pages, not just getting pages. Tested-by: Alex Bennée Signed-off-by: Sean Christopherson Tested-by: Dmitry Osipenko Signed-off-by: Paolo Bonzini Message-ID: <20241010182427.1434605-77-seanjc@google.com> --- include/linux/kvm_host.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 3e06393e5f1e..96cf9e5660c3 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1213,7 +1213,12 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm, int kvm_prefetch_pages(struct kvm_memory_slot *slot, gfn_t gfn, struct page **pages, int nr_pages); -struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn); +struct page *__gfn_to_page(struct kvm *kvm, gfn_t gfn, bool write); +static inline struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn) +{ + return __gfn_to_page(kvm, gfn, true); +} + unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn); unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable); unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t gfn); -- cgit v1.2.3