diff options
| author | Gleb Natapov <gleb@redhat.com> | 2010-01-21 15:28:46 +0200 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2010-03-01 12:36:03 -0300 |
| commit | ab344828ebe729e52949d64046adaa196f6b9dbe (patch) | |
| tree | 4dcd8ebdd8a2bb3afefb2028abd667970bf4d6ed /arch/x86/kvm/x86.c | |
| parent | f0f4b930900ffa8daddb5262522c3e5c67ee1835 (diff) | |
KVM: x86: fix checking of cr0 validity
Move to/from Control Registers chapter of Intel SDM says. "Reserved bits
in CR0 remain clear after any load of those registers; attempts to set
them have no impact". Control Register chapter says "Bits 63:32 of CR0 are
reserved and must be written with zeros. Writing a nonzero value to any
of the upper 32 bits results in a general-protection exception, #GP(0)."
This patch tries to implement this twisted logic.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Reported-by: Lorenzo Martignoni <martignlo@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index fd5101b57fa3..ce267d9f0305 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -430,12 +430,16 @@ void kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) { cr0 |= X86_CR0_ET; - if (cr0 & CR0_RESERVED_BITS) { +#ifdef CONFIG_X86_64 + if (cr0 & 0xffffffff00000000UL) { printk(KERN_DEBUG "set_cr0: 0x%lx #GP, reserved bits 0x%lx\n", cr0, kvm_read_cr0(vcpu)); kvm_inject_gp(vcpu, 0); return; } +#endif + + cr0 &= ~CR0_RESERVED_BITS; if ((cr0 & X86_CR0_NW) && !(cr0 & X86_CR0_CD)) { printk(KERN_DEBUG "set_cr0: #GP, CD == 0 && NW == 1\n"); |