| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 295/309] KVM: x86/mmu: Apply max PA check for MMIO sptes to 32-bit KVM | Date | Mon, 10 Feb 2020 04:34:11 -0800 |
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From: Sean Christopherson <sean.j.christopherson@intel.com>
[ Upstream commit e30a7d623dccdb3f880fbcad980b0cb589a1da45 ]
Remove the bogus 64-bit only condition from the check that disables MMIO spte optimization when the system supports the max PA, i.e. doesn't have any reserved PA bits. 32-bit KVM always uses PAE paging for the shadow MMU, and per Intel's SDM:
PAE paging translates 32-bit linear addresses to 52-bit physical addresses.
The kernel's restrictions on max physical addresses are limits on how much memory the kernel can reasonably use, not what physical addresses are supported by hardware.
Fixes: ce88decffd17 ("KVM: MMU: mmio page fault support") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- arch/x86/kvm/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 2ce9da58611ed..3644ac215567b 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -6249,7 +6249,7 @@ static void kvm_set_mmio_spte_mask(void) * If reserved bit is not supported, clear the present bit to disable * mmio page fault. */ - if (IS_ENABLED(CONFIG_X86_64) && shadow_phys_bits == 52) + if (shadow_phys_bits == 52) mask &= ~1ull; kvm_mmu_set_mmio_spte_mask(mask, mask, ACC_WRITE_MASK | ACC_USER_MASK); -- 2.20.1
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