From: Sean Christopherson Date: Wed, 8 Jan 2020 20:24:38 +0000 (-0800) Subject: KVM: Play nice with read-only memslots when querying host page size X-Git-Tag: v5.4.19~8 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3e3e8551a5a2537c002ac9d9fb0d68c93de303d5;p=platform%2Fkernel%2Flinux-rpi.git KVM: Play nice with read-only memslots when querying host page size [ Upstream commit 42cde48b2d39772dba47e680781a32a6c4b7dc33 ] Avoid the "writable" check in __gfn_to_hva_many(), which will always fail on read-only memslots due to gfn_to_hva() assuming writes. Functionally, this allows x86 to create large mappings for read-only memslots that are backed by HugeTLB mappings. Note, the changelog for commit 05da45583de9 ("KVM: MMU: large page support") states "If the largepage contains write-protected pages, a large pte is not used.", but "write-protected" refers to pages that are temporarily read-only, e.g. read-only memslots didn't even exist at the time. Fixes: 4d8b81abc47b ("KVM: introduce readonly memslot") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson [Redone using kvm_vcpu_gfn_to_memslot_prot. - Paolo] Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 877ce95..b5ea1ba 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1401,7 +1401,7 @@ unsigned long kvm_host_page_size(struct kvm_vcpu *vcpu, gfn_t gfn) size = PAGE_SIZE; - addr = kvm_vcpu_gfn_to_hva(vcpu, gfn); + addr = kvm_vcpu_gfn_to_hva_prot(vcpu, gfn, NULL); if (kvm_is_error_hva(addr)) return PAGE_SIZE;