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| author | Paolo Bonzini <pbonzini@redhat.com> | 2015-10-14 16:25:52 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-10-14 17:39:52 +0300 |
| commit | b10d92a54dac25a6152f1aa1ffc95c12908035ce (patch) | |
| tree | a3b91faba082c51fcd49319ef355e3783494b832 /arch | |
| parent | 25188b9986cf6b0cadcf1bc1d1693a2e9c50ed47 (diff) | |
| download | linux-b10d92a54dac25a6152f1aa1ffc95c12908035ce.tar.xz | |
KVM: x86: fix RSM into 64-bit protected mode
In order to get into 64-bit protected mode, you need to enable
paging while EFER.LMA=1. For this to work, CS.L must be 0.
Currently, we load the segments before CR0 and CR4, which means
that if RSM returns into 64-bit protected mode CS.L is already 1
and everything breaks.
Luckily, CS.L=0 is always the case when executing RSM, because it
is forbidden to execute RSM from 64-bit protected mode. Hence it
is enough to load CR0 and CR4 first, and only then the segments.
Fixes: 660a5d517aaab9187f93854425c4c63f4a09195c
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index b372a7557c16..9da95b9daf8d 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2418,7 +2418,7 @@ static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt, u64 smbase) u64 val, cr0, cr4; u32 base3; u16 selector; - int i; + int i, r; for (i = 0; i < 16; i++) *reg_write(ctxt, i) = GET_SMSTATE(u64, smbase, 0x7ff8 - i * 8); @@ -2460,13 +2460,17 @@ static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt, u64 smbase) dt.address = GET_SMSTATE(u64, smbase, 0x7e68); ctxt->ops->set_gdt(ctxt, &dt); + r = rsm_enter_protected_mode(ctxt, cr0, cr4); + if (r != X86EMUL_CONTINUE) + return r; + for (i = 0; i < 6; i++) { - int r = rsm_load_seg_64(ctxt, smbase, i); + r = rsm_load_seg_64(ctxt, smbase, i); if (r != X86EMUL_CONTINUE) return r; } - return rsm_enter_protected_mode(ctxt, cr0, cr4); + return X86EMUL_CONTINUE; } static int em_rsm(struct x86_emulate_ctxt *ctxt) |