From: Eduardo Habkost <ehabkost@xxxxxxxxxx> svm_vcpu_reset() was not properly resetting the contents of the guest-visible cr0 register, causing the following issue: https://bugzilla.redhat.com/show_bug.cgi?id=525699 Without resetting cr0 properly, the vcpu was running the SIPI bootstrap routine with paging enabled, making the vcpu get a pagefault exception while trying to run it. Instead of setting vmcb->save.cr0 directly, the new code just resets kvm->arch.cr0 and calls kvm_set_cr0(). The bits that were set/cleared on vmcb->save.cr0 (PG, WP, !CD, !NW) will be set properly by svm_set_cr0(). kvm_set_cr0() is used instead of calling svm_set_cr0() directly to make sure kvm_mmu_reset_context() is called to reset the mmu to nonpaging mode. Signed-off-by: Eduardo Habkost <ehabkost@xxxxxxxxxx> Signed-off-by: Avi Kivity <avi@xxxxxxxxxx> --- arch/x86/kvm/svm.c | 9 +++++---- 1 files changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index ffa6ad2..c9ef6c0 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -628,11 +628,12 @@ static void init_vmcb(struct vcpu_svm *svm) save->rip = 0x0000fff0; svm->vcpu.arch.regs[VCPU_REGS_RIP] = save->rip; - /* - * cr0 val on cpu init should be 0x60000010, we enable cpu - * cache by default. the orderly way is to enable cache in bios. + /* This is the guest-visible cr0 value. + * svm_set_cr0() sets PG and WP and clears NW and CD on save->cr0. */ - save->cr0 = 0x00000010 | X86_CR0_PG | X86_CR0_WP; + svm->vcpu.arch.cr0 = X86_CR0_NW | X86_CR0_CD | X86_CR0_ET; + kvm_set_cr0(&svm->vcpu, svm->vcpu.arch.cr0); + save->cr4 = X86_CR4_PAE; /* rdx = ?? */ -- 1.6.5.2 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
