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/x86.c | 2 -- 1 file changed, 2 deletions(-)
--- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6132,14 +6132,12 @@ static void kvm_set_mmio_spte_mask(void) /* Set the present bit. */ mask |= 1ull;
-#ifdef CONFIG_X86_64 /* * If reserved bit is not supported, clear the present bit to disable * mmio page fault. */ if (maxphyaddr == 52) mask &= ~1ull; -#endif
kvm_mmu_set_mmio_spte_mask(mask); }