From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
patches@lists.linux.dev, Sean Christopherson <seanjc@google.com>,
Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.1 17/46] KVM: x86: Fail emulation during EMULTYPE_SKIP on any exception
Date: Thu, 23 Feb 2023 14:06:24 +0100 [thread overview]
Message-ID: <20230223130432.341358924@linuxfoundation.org> (raw)
In-Reply-To: <20230223130431.553657459@linuxfoundation.org>
From: Sean Christopherson <seanjc@google.com>
[ Upstream commit 17122c06b86c9f77f45b86b8e62c3ed440847a59 ]
Treat any exception during instruction decode for EMULTYPE_SKIP as a
"full" emulation failure, i.e. signal failure instead of queuing the
exception. When decoding purely to skip an instruction, KVM and/or the
CPU has already done some amount of emulation that cannot be unwound,
e.g. on an EPT misconfig VM-Exit KVM has already processeed the emulated
MMIO. KVM already does this if a #UD is encountered, but not for other
exceptions, e.g. if a #PF is encountered during fetch.
In SVM's soft-injection use case, queueing the exception is particularly
problematic as queueing exceptions while injecting events can put KVM
into an infinite loop due to bailing from VM-Enter to service the newly
pending exception. E.g. multiple warnings to detect such behavior fire:
------------[ cut here ]------------
WARNING: CPU: 3 PID: 1017 at arch/x86/kvm/x86.c:9873 kvm_arch_vcpu_ioctl_run+0x1de5/0x20a0 [kvm]
Modules linked in: kvm_amd ccp kvm irqbypass
CPU: 3 PID: 1017 Comm: svm_nested_soft Not tainted 6.0.0-rc1+ #220
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:kvm_arch_vcpu_ioctl_run+0x1de5/0x20a0 [kvm]
Call Trace:
kvm_vcpu_ioctl+0x223/0x6d0 [kvm]
__x64_sys_ioctl+0x85/0xc0
do_syscall_64+0x2b/0x50
entry_SYSCALL_64_after_hwframe+0x46/0xb0
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
WARNING: CPU: 3 PID: 1017 at arch/x86/kvm/x86.c:9987 kvm_arch_vcpu_ioctl_run+0x12a3/0x20a0 [kvm]
Modules linked in: kvm_amd ccp kvm irqbypass
CPU: 3 PID: 1017 Comm: svm_nested_soft Tainted: G W 6.0.0-rc1+ #220
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:kvm_arch_vcpu_ioctl_run+0x12a3/0x20a0 [kvm]
Call Trace:
kvm_vcpu_ioctl+0x223/0x6d0 [kvm]
__x64_sys_ioctl+0x85/0xc0
do_syscall_64+0x2b/0x50
entry_SYSCALL_64_after_hwframe+0x46/0xb0
---[ end trace 0000000000000000 ]---
Fixes: 6ea6e84309ca ("KVM: x86: inject exceptions produced by x86_decode_insn")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220930233632.1725475-1-seanjc@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/kvm/x86.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 05ca303d7fd98..68827b8dc37a5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8860,7 +8860,9 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
write_fault_to_spt,
emulation_type))
return 1;
- if (ctxt->have_exception) {
+
+ if (ctxt->have_exception &&
+ !(emulation_type & EMULTYPE_SKIP)) {
/*
* #UD should result in just EMULATION_FAILED, and trap-like
* exception should not be encountered during decode.
--
2.39.0
next prev parent reply other threads:[~2023-02-23 13:08 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-23 13:06 [PATCH 6.1 00/46] 6.1.14-rc1 review Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 01/46] drm/etnaviv: dont truncate physical page address Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 02/46] wifi: ath11k: fix warning in dma_free_coherent() of memory chunks while recovery Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 03/46] wifi: rtl8xxxu: gen2: Turn on the rate control Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 04/46] drm/edid: Fix minimum bpc supported with DSC1.2 for HDMI sink Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 05/46] clk: mxl: Switch from direct readl/writel based IO to regmap based IO Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 06/46] clk: mxl: Remove redundant spinlocks Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 07/46] clk: mxl: Add option to override gate clks Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 08/46] clk: mxl: Fix a clk entry by adding relevant flags Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 09/46] powerpc: dts: t208x: Mark MAC1 and MAC2 as 10G Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 10/46] clk: mxl: syscon_node_to_regmap() returns error pointers Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 11/46] sched/psi: Stop relying on timer_pending() for poll_work rescheduling Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 12/46] random: always mix cycle counter in add_latent_entropy() Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 13/46] scsi: libsas: Add smp_ata_check_ready_type() Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 14/46] scsi: hisi_sas: Fix SATA devices missing issue during I_T nexus reset Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 15/46] spi: mediatek: Enable irq when pdata is ready Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 16/46] docs: perf: Fix PMU instance name of hisi-pcie-pmu Greg Kroah-Hartman
2023-02-23 13:06 ` Greg Kroah-Hartman [this message]
2023-02-23 13:06 ` [PATCH 6.1 18/46] KVM: SVM: Skip WRMSR fastpath on VM-Exit if next RIP isnt valid Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 19/46] KVM: VMX: Execute IBPB on emulated VM-exit when guest has IBRS Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 20/46] can: kvaser_usb: hydra: help gcc-13 to figure out cmd_len Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 21/46] powerpc: dts: t208x: Disable 10G on MAC1 and MAC2 Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 22/46] spi: mediatek: Enable irq before the spi registration Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 23/46] drm/i915: Remove __maybe_unused from mtl_info Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 24/46] KVM: x86: fix deadlock for KVM_XEN_EVTCHN_RESET Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 25/46] selftests: kvm: move declaration at the beginning of main() Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 26/46] powerpc/64s/radix: Fix RWX mapping with relocated kernel Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 27/46] nfp: ethtool: support reporting link modes Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 28/46] nfp: ethtool: fix the bug of setting unsupported port speed Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 29/46] uaccess: Add speculation barrier to copy_from_user() Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 30/46] x86/alternatives: Introduce int3_emulate_jcc() Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 31/46] x86/alternatives: Teach text_poke_bp() to patch Jcc.d32 instructions Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 32/46] x86/static_call: Add support for Jcc tail-calls Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 33/46] Bluetooth: btusb: Add more device IDs for WCN6855 Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 34/46] riscv: remove special treatment for the link order of head.o Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 35/46] arm64: " Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 36/46] arch: fix broken BuildID for arm64 and riscv Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 37/46] powerpc/vmlinux.lds: Define RUNTIME_DISCARD_EXIT Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 38/46] powerpc/vmlinux.lds: Dont discard .rela* for relocatable builds Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 39/46] s390: define RUNTIME_DISCARD_EXIT to fix link error with GNU ld < 2.36 Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 40/46] sh: define RUNTIME_DISCARD_EXIT Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 41/46] wifi: mwifiex: Add missing compatible string for SD8787 Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 42/46] audit: update the mailing list in MAINTAINERS Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 43/46] platform/x86/amd/pmf: Add depends on CONFIG_POWER_SUPPLY Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 44/46] platform/x86: nvidia-wmi-ec-backlight: Add force module parameter Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 45/46] ext4: Fix function prototype mismatch for ext4_feat_ktype Greg Kroah-Hartman
2023-02-23 13:06 ` [PATCH 6.1 46/46] randstruct: disable Clang 15 support Greg Kroah-Hartman
2023-02-23 14:33 ` [PATCH 6.1 00/46] 6.1.14-rc1 review Conor Dooley
2023-02-23 14:37 ` Greg Kroah-Hartman
2023-02-23 14:41 ` Conor Dooley
2023-02-23 14:38 ` Naresh Kamboju
2023-02-23 16:31 ` Greg Kroah-Hartman
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