Commit cbe3f898 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Paolo Bonzini
Browse files

x86/kvm/nVMX: tweak shadow fields 



It seems we have some leftovers from times when 'unrestricted guest'
wasn't exposed to L1. Stop shadowing GUEST_CS_{BASE,LIMIT,AR_SELECTOR}
and GUEST_ES_BASE, shadow GUEST_SS_AR_BYTES as it was found that some
hypervisors (e.g. Hyper-V without Enlightened VMCS) access it pretty
often.

Suggested-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent f15ac811

arch/x86/kvm/vmx.c

+5 −5
Original line number Diff line number Diff line
@@ -12715,6 +12715,7 @@ static void prepare_vmcs02_full(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12) 
	if (!hv_evmcs || !(hv_evmcs->hv_clean_fields &

			   HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP2)) {

		vmcs_write16(GUEST_ES_SELECTOR, vmcs12->guest_es_selector);

		vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector);

		vmcs_write16(GUEST_SS_SELECTOR, vmcs12->guest_ss_selector);

		vmcs_write16(GUEST_DS_SELECTOR, vmcs12->guest_ds_selector);

		vmcs_write16(GUEST_FS_SELECTOR, vmcs12->guest_fs_selector);
@@ -12722,6 +12723,7 @@ static void prepare_vmcs02_full(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12) 
		vmcs_write16(GUEST_LDTR_SELECTOR, vmcs12->guest_ldtr_selector);

		vmcs_write16(GUEST_TR_SELECTOR, vmcs12->guest_tr_selector);

		vmcs_write32(GUEST_ES_LIMIT, vmcs12->guest_es_limit);

		vmcs_write32(GUEST_CS_LIMIT, vmcs12->guest_cs_limit);

		vmcs_write32(GUEST_SS_LIMIT, vmcs12->guest_ss_limit);

		vmcs_write32(GUEST_DS_LIMIT, vmcs12->guest_ds_limit);

		vmcs_write32(GUEST_FS_LIMIT, vmcs12->guest_fs_limit);
@@ -12731,12 +12733,13 @@ static void prepare_vmcs02_full(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12) 
		vmcs_write32(GUEST_GDTR_LIMIT, vmcs12->guest_gdtr_limit);

		vmcs_write32(GUEST_IDTR_LIMIT, vmcs12->guest_idtr_limit);

		vmcs_write32(GUEST_ES_AR_BYTES, vmcs12->guest_es_ar_bytes);

		vmcs_write32(GUEST_SS_AR_BYTES, vmcs12->guest_ss_ar_bytes);

		vmcs_write32(GUEST_DS_AR_BYTES, vmcs12->guest_ds_ar_bytes);

		vmcs_write32(GUEST_FS_AR_BYTES, vmcs12->guest_fs_ar_bytes);

		vmcs_write32(GUEST_GS_AR_BYTES, vmcs12->guest_gs_ar_bytes);

		vmcs_write32(GUEST_LDTR_AR_BYTES, vmcs12->guest_ldtr_ar_bytes);

		vmcs_write32(GUEST_TR_AR_BYTES, vmcs12->guest_tr_ar_bytes);

		vmcs_writel(GUEST_ES_BASE, vmcs12->guest_es_base);

		vmcs_writel(GUEST_CS_BASE, vmcs12->guest_cs_base);

		vmcs_writel(GUEST_SS_BASE, vmcs12->guest_ss_base);

		vmcs_writel(GUEST_DS_BASE, vmcs12->guest_ds_base);

		vmcs_writel(GUEST_FS_BASE, vmcs12->guest_fs_base);
@@ -12838,11 +12841,8 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, 
	 */

	if (!hv_evmcs || !(hv_evmcs->hv_clean_fields &

			   HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP2)) {

		vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector);

		vmcs_write32(GUEST_CS_LIMIT, vmcs12->guest_cs_limit);

		vmcs_write32(GUEST_CS_AR_BYTES, vmcs12->guest_cs_ar_bytes);

		vmcs_writel(GUEST_ES_BASE, vmcs12->guest_es_base);

		vmcs_writel(GUEST_CS_BASE, vmcs12->guest_cs_base);

		vmcs_write32(GUEST_SS_AR_BYTES, vmcs12->guest_ss_ar_bytes);

	}



	if (vmx->nested.nested_run_pending &&

arch/x86/kvm/vmx_shadow_fields.h

+1 −4
Original line number Diff line number Diff line
@@ -28,7 +28,6 @@ 
 */



/* 16-bits */

SHADOW_FIELD_RW(GUEST_CS_SELECTOR)

SHADOW_FIELD_RW(GUEST_INTR_STATUS)

SHADOW_FIELD_RW(GUEST_PML_INDEX)

SHADOW_FIELD_RW(HOST_FS_SELECTOR)
@@ -47,8 +46,8 @@ SHADOW_FIELD_RW(VM_ENTRY_EXCEPTION_ERROR_CODE) 
SHADOW_FIELD_RW(VM_ENTRY_INTR_INFO_FIELD)

SHADOW_FIELD_RW(VM_ENTRY_INSTRUCTION_LEN)

SHADOW_FIELD_RW(TPR_THRESHOLD)

SHADOW_FIELD_RW(GUEST_CS_LIMIT)

SHADOW_FIELD_RW(GUEST_CS_AR_BYTES)

SHADOW_FIELD_RW(GUEST_SS_AR_BYTES)

SHADOW_FIELD_RW(GUEST_INTERRUPTIBILITY_INFO)

SHADOW_FIELD_RW(VMX_PREEMPTION_TIMER_VALUE)
@@ -61,8 +60,6 @@ SHADOW_FIELD_RW(GUEST_CR0) 
SHADOW_FIELD_RW(GUEST_CR3)

SHADOW_FIELD_RW(GUEST_CR4)

SHADOW_FIELD_RW(GUEST_RFLAGS)

SHADOW_FIELD_RW(GUEST_CS_BASE)

SHADOW_FIELD_RW(GUEST_ES_BASE)

SHADOW_FIELD_RW(CR0_GUEST_HOST_MASK)

SHADOW_FIELD_RW(CR0_READ_SHADOW)

SHADOW_FIELD_RW(CR4_READ_SHADOW)

CRA Git | Maintained and supported by SUSTech CRA and CCSE