[PATCH 9/9] kvm: vmx: add nested virtualization support for xsaves

Paolo Bonzini
2014-12-04T15:57:14Z

From: Wanpeng Li <wanpeng.li@linux.intel.com>

Add vmcs12 support for xsaves.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/vmx.c | 23 ++++++++++++++++++++++-
1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ad1153a725a2..9bcc871f0635 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -216,6 +216,7 @@ struct __packed vmcs12 {
u64 virtual_apic_page_addr;
u64 apic_access_addr;
u64 ept_pointer;
+ u64 xss_exit_bitmap;
u64 guest_physical_address;
u64 vmcs_link_pointer;
u64 guest_ia32_debugctl;
@@ -618,6 +619,7 @@ static const unsigned short vmcs_field_to_offset_table[] = {
FIELD64(VIRTUAL_APIC_PAGE_ADDR, virtual_apic_page_addr),
FIELD64(APIC_ACCESS_ADDR, apic_access_addr),
FIELD64(EPT_POINTER, ept_pointer),
+ FIELD64(XSS_EXIT_BITMAP, xss_exit_bitmap),
FIELD64(GUEST_PHYSICAL_ADDRESS, guest_physical_address),
FIELD64(VMCS_LINK_POINTER, vmcs_link_pointer),
FIELD64(GUEST_IA32_DEBUGCTL, guest_ia32_debugctl),
@@ -1104,6 +1106,12 @@ static inline int nested_cpu_has_ept(struct vmcs12 *vmcs12)
return nested_cpu_has2(vmcs12, SECONDARY_EXEC_ENABLE_EPT);
}

+static inline bool nested_cpu_has_xsaves(struct vmcs12 *vmcs12)
+{
+ return nested_cpu_has2(vmcs12, SECONDARY_EXEC_XSAVES) &&
+ vmx_xsaves_supported();
+}
+
static inline bool is_exception(u32 intr_info)
{
return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VALID_MASK))
@@ -2392,7 +2400,8 @@ static __init void nested_vmx_setup_ctls_msrs(void)
nested_vmx_secondary_ctls_high &=
SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
SECONDARY_EXEC_UNRESTRICTED_GUEST |
- SECONDARY_EXEC_WBINVD_EXITING;
+ SECONDARY_EXEC_WBINVD_EXITING |
+ SECONDARY_EXEC_XSAVES;

if (enable_ept) {
/* nested EPT: emulate EPT also to L1 */
@@ -7286,6 +7295,14 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
return nested_cpu_has2(vmcs12, SECONDARY_EXEC_WBINVD_EXITING);
case EXIT_REASON_XSETBV:
return 1;
+ case EXIT_REASON_XSAVES: case EXIT_REASON_XRSTORS:
+ /*
+ * This should never happen, since it is not possible to
+ * set XSS to a non-zero value---neither in L1 nor in L2.
+ * If if it were, XSS would have to be checked against
+ * the XSS exit bitmap in vmcs12.
+ */
+ return nested_cpu_has2(vmcs12, SECONDARY_EXEC_XSAVES);
default:
return 1;
}
@@ -8342,6 +8359,8 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
vmcs_writel(GUEST_SYSENTER_ESP, vmcs12->guest_sysenter_esp);
vmcs_writel(GUEST_SYSENTER_EIP, vmcs12->guest_sysenter_eip);

+ if (nested_cpu_has_xsaves(vmcs12))
+ vmcs_write64(XSS_EXIT_BITMAP, vmcs12->xss_exit_bitmap);
vmcs_write64(VMCS_LINK_POINTER, -1ull);

exec_control = vmcs12->pin_based_vm_exec_control;
@@ -8982,6 +9001,8 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
vmcs12->guest_sysenter_eip = vmcs_readl(GUEST_SYSENTER_EIP);
if (vmx_mpx_supported())
vmcs12->guest_bndcfgs = vmcs_read64(GUEST_BNDCFGS);
+ if (nested_cpu_has_xsaves(vmcs12))
+ vmcs12->xss_exit_bitmap = vmcs_read64(XSS_EXIT_BITMAP);

/* update exit information fields: */

--
1.8.3.1