From 365e319208442a0807a96e9ea4d0b1fa338f1929 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 10 Oct 2024 11:23:35 -0700 Subject: KVM: Pass in write/dirty to kvm_vcpu_map(), not kvm_vcpu_unmap() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Now that all kvm_vcpu_{,un}map() users pass "true" for @dirty, have them pass "true" as a @writable param to kvm_vcpu_map(), and thus create a read-only mapping when possible. Note, creating read-only mappings can be theoretically slower, as they don't play nice with fast GUP due to the need to break CoW before mapping the underlying PFN. But practically speaking, creating a mapping isn't a super hot path, and getting a writable mapping for reading is weird and confusing. Tested-by: Alex Bennée Signed-off-by: Sean Christopherson Tested-by: Dmitry Osipenko Signed-off-by: Paolo Bonzini Message-ID: <20241010182427.1434605-34-seanjc@google.com> --- include/linux/kvm_host.h | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index b4c541fa5a1f..101dbf2be1ce 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -285,6 +285,7 @@ struct kvm_host_map { void *hva; kvm_pfn_t pfn; kvm_pfn_t gfn; + bool writable; }; /* @@ -1311,8 +1312,23 @@ void mark_page_dirty(struct kvm *kvm, gfn_t gfn); struct kvm_memslots *kvm_vcpu_memslots(struct kvm_vcpu *vcpu); struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn); -int kvm_vcpu_map(struct kvm_vcpu *vcpu, gpa_t gpa, struct kvm_host_map *map); -void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty); + +int __kvm_vcpu_map(struct kvm_vcpu *vcpu, gpa_t gpa, struct kvm_host_map *map, + bool writable); +void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map); + +static inline int kvm_vcpu_map(struct kvm_vcpu *vcpu, gpa_t gpa, + struct kvm_host_map *map) +{ + return __kvm_vcpu_map(vcpu, gpa, map, true); +} + +static inline int kvm_vcpu_map_readonly(struct kvm_vcpu *vcpu, gpa_t gpa, + struct kvm_host_map *map) +{ + return __kvm_vcpu_map(vcpu, gpa, map, false); +} + unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn); unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable); int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data, int offset, -- cgit v1.2.3