From 6b26d90d125a1bceee429cb2b839bae8ac8b8b38 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 7 Jan 2020 16:12:10 -0800 Subject: [PATCH] KVM: x86/mmu: Apply max PA check for MMIO sptes to 32-bit KVM [ 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 Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- arch/x86/kvm/x86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d915ea0e69cf..d6851636edab 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6314,7 +6314,7 @@ 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) && maxphyaddr == 52) + if (maxphyaddr == 52) mask &= ~1ull; kvm_mmu_set_mmio_spte_mask(mask, mask);