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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2014-09-12 17:16:00 +0400 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2016-11-29 00:22:48 +0300 |
| commit | 79024d0fdd8b839a0c7664e4027f4e6be99eb2be (patch) | |
| tree | 19b49a045fbb751bc9e040a73e5c73b3c4e29efb /virt/kvm | |
| parent | 571a8e0bf6d7ca990a13ad9622f3880244c11573 (diff) | |
| download | linux-79024d0fdd8b839a0c7664e4027f4e6be99eb2be.tar.xz | |
KVM: check for !is_zero_pfn() in kvm_is_mmio_pfn()
commit 85c8555ff07ef09261bd50d603cd4290cff5a8cc upstream.
Read-only memory ranges may be backed by the zero page, so avoid
misidentifying it a a MMIO pfn.
This fixes another issue I identified when testing QEMU+KVM_UEFI, where
a read to an uninitialized emulated NOR flash brought in the zero page,
but mapped as a read-write device region, because kvm_is_mmio_pfn()
misidentifies it as a MMIO pfn due to its PG_reserved bit being set.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Fixes: b88657674d39 ("ARM: KVM: user_mem_abort: support stage 2 MMIO page mapping")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'virt/kvm')
| -rw-r--r-- | virt/kvm/kvm_main.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 3351605d2608..e7a1166c3eb4 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -104,7 +104,7 @@ static bool largepages_enabled = true; bool kvm_is_mmio_pfn(pfn_t pfn) { if (pfn_valid(pfn)) - return PageReserved(pfn_to_page(pfn)); + return !is_zero_pfn(pfn) && PageReserved(pfn_to_page(pfn)); return true; } |