linux-kernel - [PATCH 08/18] KVM: Handle guest page faults when emulating mmio

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 26 Apr 2007 12:22:08 +0300
From:	Avi Kivity <avi@...ranet.com>
To:	kvm-devel@...ts.sourceforge.net
Cc:	linux-kernel@...r.kernel.org, Avi Kivity <avi@...ranet.com>
Subject: [PATCH 08/18] KVM: Handle guest page faults when emulating mmio

Usually, guest page faults are detected by the kvm page fault handler,
which detects if they are shadow faults, mmio faults, pagetable faults,
or normal guest page faults.

However, in ceratin circumstances, we can detect a page fault much later.
One of these events is the following combination:

- A two memory operand instruction (e.g. movsb) is executed.
- The first operand is in mmio space (which is the fault reported to kvm)
- The second operand is in an ummaped address (e.g. a guest page fault)

The Windows 2000 installer does such an access, an promptly hangs.  Fix
by adding the missing page fault injection on that path.

Signed-off-by: Avi Kivity <avi@...ranet.com>
---
 drivers/kvm/kvm_main.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index ab4dbd7..03c0ee7 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1071,8 +1071,10 @@ static int emulator_write_emulated(unsigned long addr,
 	struct kvm_vcpu *vcpu = ctxt->vcpu;
 	gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
 
-	if (gpa == UNMAPPED_GVA)
+	if (gpa == UNMAPPED_GVA) {
+		kvm_arch_ops->inject_page_fault(vcpu, addr, 2);
 		return X86EMUL_PROPAGATE_FAULT;
+	}
 
 	if (emulator_write_phys(vcpu, gpa, val, bytes))
 		return X86EMUL_CONTINUE;
-- 
1.5.0.6

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/