KVM: X86: Processor States following Reset or INIT

- XCR0 is reset to 1 by RESET but not INIT
- XSS is zeroed by both RESET and INIT
- BNDCFGU, BND0-BND3, BNDCFGS, BNDSTATUS are zeroed by both RESET and INIT

This patch does this according to SDM.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Jim Mattson <jmattson@google.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ffea07e..cbd7afa 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5581,6 +5581,8 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
        vmcs_write32(GUEST_ACTIVITY_STATE, GUEST_ACTIVITY_ACTIVE);
        vmcs_write32(GUEST_INTERRUPTIBILITY_INFO, 0);
        vmcs_writel(GUEST_PENDING_DBG_EXCEPTIONS, 0);
+       if (kvm_mpx_supported())
+               vmcs_write64(GUEST_BNDCFGS, 0);
 
        setup_msrs(vmx);
 

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b0d2915..4ac2610 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7804,18 +7804,40 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
        kvm_async_pf_hash_reset(vcpu);
        vcpu->arch.apf.halted = false;
 
+       if (kvm_mpx_supported()) {
+               void *mpx_state_buffer;
+
+               /*
+                * To avoid have the INIT path from kvm_apic_has_events() that be
+                * called with loaded FPU and does not let userspace fix the state.
+                */
+               kvm_put_guest_fpu(vcpu);
+               mpx_state_buffer = get_xsave_addr(&vcpu->arch.guest_fpu.state.xsave,
+                                       XFEATURE_MASK_BNDREGS);
+               if (mpx_state_buffer)
+                       memset(mpx_state_buffer, 0, sizeof(struct mpx_bndreg_state));
+               mpx_state_buffer = get_xsave_addr(&vcpu->arch.guest_fpu.state.xsave,
+                                       XFEATURE_MASK_BNDCSR);
+               if (mpx_state_buffer)
+                       memset(mpx_state_buffer, 0, sizeof(struct mpx_bndcsr));
+       }
+
        if (!init_event) {
                kvm_pmu_reset(vcpu);
                vcpu->arch.smbase = 0x30000;
 
                vcpu->arch.msr_platform_info = MSR_PLATFORM_INFO_CPUID_FAULT;
                vcpu->arch.msr_misc_features_enables = 0;
+
+               vcpu->arch.xcr0 = XFEATURE_MASK_FP;
        }
 
        memset(vcpu->arch.regs, 0, sizeof(vcpu->arch.regs));
        vcpu->arch.regs_avail = ~0;
        vcpu->arch.regs_dirty = ~0;
 
+       vcpu->arch.ia32_xss = 0;
+
        kvm_x86_ops->vcpu_reset(vcpu, init_event);
 }