[PATCH v2 1/2] KVM: X86: Processor States following Reset or INIT

From: Wanpeng Li
Date: Mon Oct 09 2017 - 07:01:03 EST


From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>

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

This patch does this according to SDM.

Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
Cc: Jim Mattson <jmattson@xxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
---
v1 -> v2:
* XCR0 is not zeroed by INIT
* XSS, BNDCFGU, BND0-BND3, BNDCFGS are zeroed by both RESET and INIT

arch/x86/kvm/vmx.c | 2 ++
arch/x86/kvm/x86.c | 11 +++++++++++
2 files changed, 13 insertions(+)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 244e366..ab0f16e 100644
--- 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..f353825 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7804,18 +7804,29 @@ 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()) {
+ memset(get_xsave_addr(&vcpu->arch.guest_fpu.state.xsave,
+ XFEATURE_MASK_BNDREGS), 0, sizeof(struct mpx_bndreg_state));
+ memset(get_xsave_addr(&vcpu->arch.guest_fpu.state.xsave,
+ XFEATURE_MASK_BNDCSR), 0, sizeof(u64));
+ }
+
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);
}

--
2.7.4