999512f123
- vdpa: suspend function return 0 when the vdpa device is stopped - vdpa: don't suspend/resume device when vdpa device not started - vdpa: support vdpa device suspend/resume - vdpa: correct param passed in when unregister save - vdpa: set vring enable only if the vring address has already been set - shadow_dev: introduce shadow dev for virtio-net device - revert "tcg/loongarch64: Fix tcg_out_mov() Aborted" - migration: Set downtime_start even for postcopy - gdb-xml: fix duplicate register in arm-neon.xml - iotests: fix default machine type detection - migration: fix RAMBlock add NULL check - s390x: Fix spelling errors - ppc: spelling fixes - hw/scsi/vhost-scsi: don't double close vhostfd on error - virtio/vhost-vsock: don't double close vhostfd, remove redundant cleanup - hw/scsi/vhost-scsi: don't leak vqs on error - hw/i386/pc: Add missing property descriptions - pcie_aer: Don't trigger a LSI if none are defined - pci: Export the pci_intx() function - hw/qdev: Cosmetic around documentation - tests/unit: fix a -Wformat-truncation warning - tests/avocado: mark ReplayKernelNormal.test_mips64el_malta as flaky - i386/sev: Avoid SEV-ES crash due to missing MSR_EFER_LMA bit - ui/vnc-clipboard: fix inflate_buffer - hw/usb/hcd-xhci.c: spelling: tranfer Signed-off-by: Jiabo Feng <fengjiabo1@huawei.com> (cherry picked from commit 68fee7dc06a6beb5f69d951e22a7f16091f269ff)
74 lines
3.2 KiB
Diff
74 lines
3.2 KiB
Diff
From 92b95a2982e192b90b45a988afe81e253862690f Mon Sep 17 00:00:00 2001
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From: tangzhongrui <tangzhongrui@cmss.chinamobile.com>
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Date: Thu, 7 Dec 2023 20:06:08 +0800
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Subject: [PATCH] i386/sev: Avoid SEV-ES crash due to missing MSR_EFER_LMA
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bit
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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Commit 7191f24c7fcf ("accel/kvm/kvm-all: Handle register access errors")
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added error checking for KVM_SET_SREGS/KVM_SET_SREGS2. In doing so, it
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exposed a long-running bug in current KVM support for SEV-ES where the
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kernel assumes that MSR_EFER_LMA will be set explicitly by the guest
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kernel, in which case EFER write traps would result in KVM eventually
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seeing MSR_EFER_LMA get set and recording it in such a way that it would
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be subsequently visible when accessing it via KVM_GET_SREGS/etc.
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However, guest kernels currently rely on MSR_EFER_LMA getting set
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automatically when MSR_EFER_LME is set and paging is enabled via
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CR0_PG_MASK. As a result, the EFER write traps don't actually expose the
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MSR_EFER_LMA bit, even though it is set internally, and when QEMU
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subsequently tries to pass this EFER value back to KVM via
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KVM_SET_SREGS* it will fail various sanity checks and return -EINVAL,
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which is now considered fatal due to the aforementioned QEMU commit.
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This can be addressed by inferring the MSR_EFER_LMA bit being set when
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paging is enabled and MSR_EFER_LME is set, and synthesizing it to ensure
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the expected bits are all present in subsequent handling on the host
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side.
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Ultimately, this handling will be implemented in the host kernel, but to
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avoid breaking QEMU's SEV-ES support when using older host kernels, the
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same handling can be done in QEMU just after fetching the register
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values via KVM_GET_SREGS*. Implement that here.
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Cc: Paolo Bonzini <pbonzini@redhat.com>
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Cc: Marcelo Tosatti <mtosatti@redhat.com>
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Cc: Tom Lendacky <thomas.lendacky@amd.com>
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Cc: Akihiko Odaki <akihiko.odaki@daynix.com>
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Cc: Philippe Mathieu-Daudé <philmd@linaro.org>
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Cc: Lara Lazier <laramglazier@gmail.com>
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Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
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Cc: Maxim Levitsky <mlevitsk@redhat.com>
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Cc: <kvm@vger.kernel.org>
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Fixes: 7191f24c7fcf ("accel/kvm/kvm-all: Handle register access errors")
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Signed-off-by: Michael Roth <michael.roth@amd.com>
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Acked-by: Paolo Bonzini <pbonzini@redhat.com>
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Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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Message-ID: <20231206155821.1194551-1-michael.roth@amd.com>
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Signed-off-by: Zhongrui Tang <tangzhongrui@cmss.chinamobile.com>
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---
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target/i386/kvm/kvm.c | 4 ++++
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1 file changed, 4 insertions(+)
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diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
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index 55ee75e844..54e48530ad 100644
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--- a/target/i386/kvm/kvm.c
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+++ b/target/i386/kvm/kvm.c
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@@ -3420,6 +3420,10 @@ static int kvm_get_sregs(X86CPU *cpu)
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env->cr[4] = sregs.cr4;
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env->efer = sregs.efer;
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+ if (sev_es_enabled() && env->efer & MSR_EFER_LME &&
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+ env->cr[0] & CR0_PG_MASK) {
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+ env->efer |= MSR_EFER_LMA;
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+ }
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/* changes to apic base and cr8/tpr are read back via kvm_arch_post_run */
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x86_update_hflags(env);
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--
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2.27.0
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