Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 64f7a115 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: vmx: update sec exec controls for UMIP iff emulating UMIP 



Update SECONDARY_EXEC_DESC for UMIP emulation if and only UMIP
is actually being emulated.  Skipping the VMCS update eliminates
unnecessary VMREAD/VMWRITE when UMIP is supported in hardware,
and on platforms that don't have SECONDARY_VM_EXEC_CONTROL.  The
latter case resolves a bug where KVM would fill the kernel log
with warnings due to failed VMWRITEs on older platforms.

Fixes: 0367f205 ("KVM: vmx: add support for emulating UMIP")
Cc: stable@vger.kernel.org #4.16
Reported-by: default avatarPaolo Zeppegno <pzeppegno@gmail.com>
Suggested-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Suggested-by: default avatarRadim KrÄmář <rkrcmar@redhat.com>
Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent c19986fe

arch/x86/kvm/vmx.c

+15 −13
Original line number Diff line number Diff line
@@ -1494,6 +1494,12 @@ static inline bool cpu_has_vmx_vmfunc(void) 
		SECONDARY_EXEC_ENABLE_VMFUNC;

}



static bool vmx_umip_emulated(void)

{

	return vmcs_config.cpu_based_2nd_exec_ctrl &

		SECONDARY_EXEC_DESC;

}



static inline bool report_flexpriority(void)

{

	return flexpriority_enabled;
@@ -4761,7 +4767,8 @@ static int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) 
	else

		hw_cr4 |= KVM_PMODE_VM_CR4_ALWAYS_ON;



	if ((cr4 & X86_CR4_UMIP) && !boot_cpu_has(X86_FEATURE_UMIP)) {

	if (!boot_cpu_has(X86_FEATURE_UMIP) && vmx_umip_emulated()) {

		if (cr4 & X86_CR4_UMIP) {

			vmcs_set_bits(SECONDARY_VM_EXEC_CONTROL,

				SECONDARY_EXEC_DESC);

			hw_cr4 &= ~X86_CR4_UMIP;
@@ -4769,6 +4776,7 @@ static int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) 
			!nested_cpu_has2(get_vmcs12(vcpu), SECONDARY_EXEC_DESC))

			vmcs_clear_bits(SECONDARY_VM_EXEC_CONTROL,

					SECONDARY_EXEC_DESC);

	}



	if (cr4 & X86_CR4_VMXE) {

		/*
@@ -9497,12 +9505,6 @@ static bool vmx_xsaves_supported(void) 
		SECONDARY_EXEC_XSAVES;

}



static bool vmx_umip_emulated(void)

{

	return vmcs_config.cpu_based_2nd_exec_ctrl &

		SECONDARY_EXEC_DESC;

}



static void vmx_recover_nmi_blocking(struct vcpu_vmx *vmx)

{

	u32 exit_intr_info;