patches/kernel/0008-KVM-x86-emulator-update-the-emulation-mode-after-rsm.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Maxim Levitsky <mlevitsk@redhat.com>
   3 Date: Wed, 3 Aug 2022 18:50:02 +0300
   4 Subject: [PATCH] KVM: x86: emulator: update the emulation mode after rsm
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   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 This ensures that RIP will be correctly written back,
  10 because the RSM instruction can switch the CPU mode from
  11 32 bit (or less) to 64 bit.
  12
  13 This fixes a guest crash in case the #SMI is received
  14 while the guest runs a code from an address > 32 bit.
  15
  16 Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
  17 Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
  18 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
  19 ---
  20  arch/x86/kvm/emulate.c | 5 +++++
  21  1 file changed, 5 insertions(+)
  22
  23 diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
  24 index 4a43261d25a2..4f7f5117ec7a 100644
  25 --- a/arch/x86/kvm/emulate.c
  26 +++ b/arch/x86/kvm/emulate.c
  27 @@ -2654,6 +2654,11 @@ static int em_rsm(struct x86_emulate_ctxt *ctxt)
  28         if (ret != X86EMUL_CONTINUE)
  29                 goto emulate_shutdown;
  30
  31 +
  32 +       ret = emulator_recalc_and_set_mode(ctxt);
  33 +       if (ret != X86EMUL_CONTINUE)
  34 +               goto emulate_shutdown;
  35 +
  36         /*
  37          * Note, the ctxt->ops callbacks are responsible for handling side
  38          * effects when writing MSRs and CRs, e.g. MMU context resets, CPUID