Re: Nested paging in nested SVM setup

[Paolo Bonzini <pbonzini@redhat.com>]

Il 18/06/2014 18:59, Valentine Sinitsyn ha scritto:
>
> I also noticed that setting PAT MSR from the nested hypervisor leaves
> high word unassigned, i.e. the code like this:
>
>   mov $0x70106, %rax
>   mov %rax, %rdx
>   mov $0x0277, %rcx
>   wrmsr
>   rdmsr
>
> yields %rax = 0, %rdx = 0x70106.

This should be the trivial fix:

diff --git a/arch/x86/include/asm/kvm_host.h 
b/arch/x86/include/asm/kvm_host.h
index 0b140dc65bee..8a1cdc0f8fe7 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -461,7 +461,7 @@ struct kvm_vcpu_arch {
  	bool nmi_injected;    /* Trying to inject an NMI this entry */

  	struct mtrr_state_type mtrr_state;
-	u32 pat;
+	u64 pat;

  	unsigned switch_db_regs;
  	unsigned long db[KVM_NR_DB_REGS];

Paolo