| Message ID | 1410527760-19737-1-git-send-email-ard.biesheuvel@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Il 12/09/2014 15:16, Ard Biesheuvel ha scritto: > Read-only memory ranges may be backed by the zero page, so avoid > misidentifying it a a MMIO pfn. > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > Fixes: b88657674d39 ("ARM: KVM: user_mem_abort: support stage 2 MMIO page mapping") > --- > > 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. > > virt/kvm/kvm_main.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 36b887dd0c84..f8adaabeac13 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -110,7 +110,7 @@ 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; > } > Thanks, applying to kvm/master. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 36b887dd0c84..f8adaabeac13 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -110,7 +110,7 @@ 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; }
Read-only memory ranges may be backed by the zero page, so avoid misidentifying it a a MMIO pfn. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Fixes: b88657674d39 ("ARM: KVM: user_mem_abort: support stage 2 MMIO page mapping") --- 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. virt/kvm/kvm_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)