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From: Ben Hutchings <ben@decadent.org.uk>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: akpm@linux-foundation.org, "Paolo Bonzini" <pbonzini@redhat.com>,
	"Nadav Amit" <namit@cs.technion.ac.il>
Subject: [PATCH 3.2 09/27] KVM: x86: Don't report guest userspace emulation error to userspace
Date: Mon, 29 Dec 2014 02:11:31 +0100	[thread overview]
Message-ID: <lsq.1419815491.894272372@decadent.org.uk> (raw)
In-Reply-To: <lsq.1419815490.288081487@decadent.org.uk>

3.2.66-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Nadav Amit <namit@cs.technion.ac.il>

commit a2b9e6c1a35afcc0973acb72e591c714e78885ff upstream.

Commit fc3a9157d314 ("KVM: X86: Don't report L2 emulation failures to
user-space") disabled the reporting of L2 (nested guest) emulation failures to
userspace due to race-condition between a vmexit and the instruction emulator.
The same rational applies also to userspace applications that are permitted by
the guest OS to access MMIO area or perform PIO.

This patch extends the current behavior - of injecting a #UD instead of
reporting it to userspace - also for guest userspace code.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 arch/x86/kvm/x86.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4846,7 +4846,7 @@ static int handle_emulation_failure(stru
 
 	++vcpu->stat.insn_emulation_fail;
 	trace_kvm_emulate_insn_failed(vcpu);
-	if (!is_guest_mode(vcpu)) {
+	if (!is_guest_mode(vcpu) && kvm_x86_ops->get_cpl(vcpu) == 0) {
 		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 		vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;
 		vcpu->run->internal.ndata = 0;


  parent reply	other threads:[~2014-12-29  1:16 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-29  1:11 [PATCH 3.2 00/27] 3.2.66-rc1 review Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 16/27] s390,time: revert direct ktime path for s390 clockevent device Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 10/27] x86/tls: Validate TLS entries to protect espfix Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 12/27] x86, kvm: Clear paravirt_enabled on KVM guests for espfix32's benefit Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 02/27] AHCI: Add DeviceIDs for Sunrise Point-LP SATA controller Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 11/27] [media] ttusb-dec: buffer overflow in ioctl Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 08/27] net: sctp: fix NULL pointer dereference in af->from_addr_param on malformed packet Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 13/27] move d_rcu from overlapping d_child to overlapping d_alias Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 22/27] tcp: md5: remove spinlock usage in fast path Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 15/27] ext4: make orphan functions be no-op in no-journal mode Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 21/27] ipv4: fix nexthop attlen check in fib_nh_match Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 20/27] net: sctp: fix memory leak in auth key management Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 24/27] ipv4: dst_entry leak in ip_send_unicast_reply() Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 25/27] drivers/net: macvtap and tun depend on INET Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 03/27] sata_fsl: fix error handling of irq_of_parse_and_map Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 01/27] drm/i915: Unlock panel even when LVDS is disabled Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 04/27] mm: fix swapoff hang after page migration and fork Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 26/27] net: sctp: use MAX_HEADER for headroom reserve in output path Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 18/27] crypto: ghash-clmulni-intel - use C implementation for setkey() Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 27/27] x86: kvm: use alternatives for VMCALL vs. VMMCALL if kernel text is read-only Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 05/27] ahci: disable MSI on SAMSUNG 0xa800 SSD Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 06/27] i2c: davinci: generate STP always when NACK is received Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 23/27] tcp: md5: do not use alloc_percpu() Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 14/27] deal with deadlock in d_walk() Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 07/27] udf: Avoid infinite loop when processing indirect ICBs Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 19/27] drivers/net, ipv6: Select IPv6 fragment idents for virtio UFO packets Ben Hutchings
2014-12-29  1:11 ` [PATCH 3.2 17/27] drm: fix DRM_IOCTL_MODE_GETFB handle-leak Ben Hutchings
2014-12-29  1:11 ` Ben Hutchings [this message]
2014-12-29  1:14 ` [PATCH 3.2 00/27] 3.2.66-rc1 review Ben Hutchings
2014-12-29  9:39 ` Guenter Roeck
2014-12-29 11:28   ` Ben Hutchings
2014-12-30  0:26 ` Satoru Takeuchi
2014-12-30  1:56   ` Ben Hutchings

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