From 89c8a4984fc98e625517bfe5083342d77ee35811 Mon Sep 17 00:00:00 2001 From: Janakarajan Natarajan Date: Thu, 6 Jul 2017 15:50:47 -0500 Subject: [PATCH] KVM: SVM: Enable Virtual VMLOAD VMSAVE feature MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Enable the Virtual VMLOAD VMSAVE feature. This is done by setting bit 1 at position B8h in the vmcb. The processor must have nested paging enabled, be in 64-bit mode and have support for the Virtual VMLOAD VMSAVE feature for the bit to be set in the vmcb. Signed-off-by: Janakarajan Natarajan Reviewed-by: Paolo Bonzini Signed-off-by: Radim Krčmář --- arch/x86/include/asm/svm.h | 1 + arch/x86/kvm/svm.c | 24 ++++++++++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h index 74d139352491..58fffe79e417 100644 --- a/arch/x86/include/asm/svm.h +++ b/arch/x86/include/asm/svm.h @@ -120,6 +120,7 @@ struct __attribute__ ((__packed__)) vmcb_control_area { #define AVIC_ENABLE_MASK (1 << AVIC_ENABLE_SHIFT) #define LBR_CTL_ENABLE_MASK BIT_ULL(0) +#define VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK BIT_ULL(1) #define SVM_INTERRUPT_SHADOW_MASK 1 diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 9a09f89145f2..4c98d362e3e4 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -277,6 +277,10 @@ static int avic; module_param(avic, int, S_IRUGO); #endif +/* enable/disable Virtual VMLOAD VMSAVE */ +static int vls = true; +module_param(vls, int, 0444); + /* AVIC VM ID bit masks and lock */ static DECLARE_BITMAP(avic_vm_id_bitmap, AVIC_VM_ID_NR); static DEFINE_SPINLOCK(avic_vm_id_lock); @@ -1093,6 +1097,16 @@ static __init int svm_hardware_setup(void) } } + if (vls) { + if (!npt_enabled || + !boot_cpu_has(X86_FEATURE_VIRTUAL_VMLOAD_VMSAVE) || + !IS_ENABLED(CONFIG_X86_64)) { + vls = false; + } else { + pr_info("Virtual VMLOAD VMSAVE supported\n"); + } + } + return 0; err: @@ -1280,6 +1294,16 @@ static void init_vmcb(struct vcpu_svm *svm) if (avic) avic_init_vmcb(svm); + /* + * If hardware supports Virtual VMLOAD VMSAVE then enable it + * in VMCB and clear intercepts to avoid #VMEXIT. + */ + if (vls) { + clr_intercept(svm, INTERCEPT_VMLOAD); + clr_intercept(svm, INTERCEPT_VMSAVE); + svm->vmcb->control.virt_ext |= VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK; + } + mark_all_dirty(svm->vmcb); enable_gif(svm); -- 2.20.1