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Commit 6031a61c authored by Joerg Roedel's avatar Joerg Roedel Committed by Avi Kivity
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KVM: SVM: Reliably detect if SVM was disabled by BIOS 



This patch adds an implementation to the svm is_disabled function to
detect reliably if the BIOS disabled the SVM feature in the CPU. This
fixes the issues with kernel panics when loading the kvm-amd module on
machines where SVM is available but disabled.

Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent 796fd1b2

drivers/kvm/svm.c

+6 −0
Original line number Diff line number Diff line
@@ -1735,6 +1735,12 @@ static void svm_inject_page_fault(struct kvm_vcpu *vcpu, 


static int is_disabled(void)

{

	u64 vm_cr;



	rdmsrl(MSR_VM_CR, vm_cr);

	if (vm_cr & (1 << SVM_VM_CR_SVM_DISABLE))

		return 1;



	return 0;

}

drivers/kvm/svm.h

+3 −0
Original line number Diff line number Diff line
@@ -175,8 +175,11 @@ struct __attribute__ ((__packed__)) vmcb { 
#define SVM_CPUID_FUNC 0x8000000a



#define MSR_EFER_SVME_MASK (1ULL << 12)

#define MSR_VM_CR       0xc0010114

#define MSR_VM_HSAVE_PA 0xc0010117ULL



#define SVM_VM_CR_SVM_DISABLE 4



#define SVM_SELECTOR_S_SHIFT 4

#define SVM_SELECTOR_DPL_SHIFT 5

#define SVM_SELECTOR_P_SHIFT 7