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Correctly re-init EFER state during INIT IPI

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When doing a re-initialization of a CPU core, the default state is to _not_
have 64-bit long mode enabled. This means the LME (long mode enable) and LMA
(long mode active) bits in the EFER model-specific register should be cleared.

However, the EFER state is part of the CPU environment which is
preserved by do_cpu_init(), so if EFER.LME and EFER.LMA were set at the
time an INIT IPI was received, they will remain set after the init completes.

This is contrary to what the Intel architecture manual describes and what
happens on real hardware, and it leaves the CPU in a weird state that the
guest can't clear.

To fix this, the 'efer' member of the CPUX86State structure has been moved
to an area outside the region preserved by do_cpu_init(), so that it can
be properly re-initialized by x86_cpu_reset().

Backports commit 2188cc52cb363433751f72b991d8fb05fc60e39d from qemu
This commit is contained in:
Bill Paul 2018-02-16 00:28:38 -05:00 committed by Lioncash
parent da8e73b887
commit 5b14f0ed52
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GPG key ID: 4E3C3CC1031BA9C7
1 changed files with 1 additions and 1 deletions
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2
qemu/target-i386/cpu.h
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@ -835,6 +835,7 @@ typedef struct CPUX86State {
BNDReg bnd_regs[4];
BNDCSReg bndcs_regs;
uint64_t msr_bndcfgs;
uint64_t efer;
/* Beginning of state preserved by INIT (dummy marker). */
//struct {} start_init_save;
@ -868,7 +869,6 @@ typedef struct CPUX86State {
uint32_t sysenter_cs;
target_ulong sysenter_esp;
target_ulong sysenter_eip;
uint64_t efer;
uint64_t star;
uint64_t vm_hsave;