From: Sean Christopherson Date: Mon, 30 Apr 2018 17:01:06 +0000 (-0700) Subject: KVM: vmx: update sec exec controls for UMIP iff emulating UMIP X-Git-Tag: v4.16.11~97 X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=28208a6e244636cc1a11f72a49bbe044edad9d0f;p=linux KVM: vmx: update sec exec controls for UMIP iff emulating UMIP commit 64f7a11586ab9262f00b8b6eceef6d8154921bd8 upstream. 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: 0367f205a3b7 ("KVM: vmx: add support for emulating UMIP") Cc: stable@vger.kernel.org #4.16 Reported-by: Paolo Zeppegno Suggested-by: Paolo Bonzini Suggested-by: Radim KrÄmář Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 657c93409042..4861811438ff 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1314,6 +1314,12 @@ 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; @@ -4494,14 +4500,16 @@ static int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) (to_vmx(vcpu)->rmode.vm86_active ? KVM_RMODE_VM_CR4_ALWAYS_ON : KVM_PMODE_VM_CR4_ALWAYS_ON); - if ((cr4 & X86_CR4_UMIP) && !boot_cpu_has(X86_FEATURE_UMIP)) { - vmcs_set_bits(SECONDARY_VM_EXEC_CONTROL, - SECONDARY_EXEC_DESC); - hw_cr4 &= ~X86_CR4_UMIP; - } else if (!is_guest_mode(vcpu) || - !nested_cpu_has2(get_vmcs12(vcpu), SECONDARY_EXEC_DESC)) - vmcs_clear_bits(SECONDARY_VM_EXEC_CONTROL, + 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; + } else if (!is_guest_mode(vcpu) || + !nested_cpu_has2(get_vmcs12(vcpu), SECONDARY_EXEC_DESC)) + vmcs_clear_bits(SECONDARY_VM_EXEC_CONTROL, + SECONDARY_EXEC_DESC); + } if (cr4 & X86_CR4_VMXE) { /* @@ -9243,12 +9251,6 @@ 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;