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| author | KarimAllah Ahmed <karahmed@amazon.de> | 2018-01-17 19:18:56 +0100 |
|---|---|---|
| committer | Radim Krčmář <rkrcmar@redhat.com> | 2018-01-31 18:25:33 +0100 |
| commit | a340b3e229b24a56f1c7f5826b15a3af0f4b13e5 (patch) | |
| tree | a49fd00bcff34d0d2c7b5235f14da0315ead715e /virt | |
| parent | e53175395d7e12d8474707271bc02a2814279843 (diff) | |
| download | linux-stable-a340b3e229b24a56f1c7f5826b15a3af0f4b13e5.tar.gz linux-stable-a340b3e229b24a56f1c7f5826b15a3af0f4b13e5.tar.bz2 linux-stable-a340b3e229b24a56f1c7f5826b15a3af0f4b13e5.zip | |
kvm: Map PFN-type memory regions as writable (if possible)
For EPT-violations that are triggered by a read, the pages are also mapped with
write permissions (if their memory region is also writable). That would avoid
getting yet another fault on the same page when a write occurs.
This optimization only happens when you have a "struct page" backing the memory
region. So also enable it for memory regions that do not have a "struct page".
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index b4414842b023..8af42eab126d 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1428,7 +1428,8 @@ static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault) static int hva_to_pfn_remapped(struct vm_area_struct *vma, unsigned long addr, bool *async, - bool write_fault, kvm_pfn_t *p_pfn) + bool write_fault, bool *writable, + kvm_pfn_t *p_pfn) { unsigned long pfn; int r; @@ -1454,6 +1455,8 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma, } + if (writable) + *writable = true; /* * Get a reference here because callers of *hva_to_pfn* and @@ -1519,7 +1522,7 @@ retry: if (vma == NULL) pfn = KVM_PFN_ERR_FAULT; else if (vma->vm_flags & (VM_IO | VM_PFNMAP)) { - r = hva_to_pfn_remapped(vma, addr, async, write_fault, &pfn); + r = hva_to_pfn_remapped(vma, addr, async, write_fault, writable, &pfn); if (r == -EAGAIN) goto retry; if (r < 0) |