[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20200923220425.18402-2-sean.j.christopherson@intel.com>
Date: Wed, 23 Sep 2020 15:04:22 -0700
From: Sean Christopherson <sean.j.christopherson@...el.com>
To: Paolo Bonzini <pbonzini@...hat.com>
Cc: Sean Christopherson <sean.j.christopherson@...el.com>,
Vitaly Kuznetsov <vkuznets@...hat.com>,
Wanpeng Li <wanpengli@...cent.com>,
Jim Mattson <jmattson@...gle.com>,
Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
linux-kernel@...r.kernel.org, Kai Huang <kai.huang@...el.com>
Subject: [PATCH 1/4] KVM: x86/mmu: Return -EIO if page fault returns RET_PF_INVALID
Exit to userspace with an error if the MMU is buggy and returns
RET_PF_INVALID when servicing a page fault. This will allow a future
patch to invert the emulation path, i.e. emulate only on RET_PF_EMULATE
instead of emulating on anything but RET_PF_RETRY. This technically
means that KVM will exit to userspace instead of emulating on
RET_PF_INVALID, but practically speaking it's a nop as the MMU never
returns RET_PF_INVALID.
Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
---
arch/x86/kvm/mmu/mmu.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 76c5826e29a2..4a2a8f67a8f7 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5450,7 +5450,8 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code,
if (r == RET_PF_INVALID) {
r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa,
lower_32_bits(error_code), false);
- WARN_ON(r == RET_PF_INVALID);
+ if (WARN_ON_ONCE(r == RET_PF_INVALID))
+ return -EIO;
}
if (r == RET_PF_RETRY)
--
2.28.0
Powered by blists - more mailing lists