On 06/13/2010 03:25 PM, Nadav Har'El wrote:
When the guest can use VMX instructions (when the "nested" module option is
on), it should also be able to read and write VMX MSRs, e.g., to query about
VMX capabilities. This patch adds this support.
Signed-off-by: Nadav Har'El<nyh@xxxxxxxxxx>
---
--- .before/arch/x86/kvm/x86.c 2010-06-13 15:01:28.000000000 +0300
+++ .after/arch/x86/kvm/x86.c 2010-06-13 15:01:28.000000000 +0300
@@ -702,7 +702,11 @@ static u32 msrs_to_save[] = {
#ifdef CONFIG_X86_64
MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
#endif
- MSR_IA32_TSC, MSR_IA32_PERF_STATUS, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA
+ MSR_IA32_TSC, MSR_IA32_PERF_STATUS, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA,
+ MSR_IA32_FEATURE_CONTROL, MSR_IA32_VMX_BASIC,
+ MSR_IA32_VMX_PINBASED_CTLS, MSR_IA32_VMX_PROCBASED_CTLS,
+ MSR_IA32_VMX_EXIT_CTLS, MSR_IA32_VMX_ENTRY_CTLS,
+ MSR_IA32_VMX_PROCBASED_CTLS2, MSR_IA32_VMX_EPT_VPID_CAP,
};
These are read only from the guest point of view, but we need write
support from the host to allow for tuning the features exposed to the guest.
/*
+ * If we allow our guest to use VMX instructions, we should also let it use
+ * VMX-specific MSRs.
+ */
+static int nested_vmx_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
+{
+ u64 vmx_msr = 0;
+ u32 vmx_msr_high, vmx_msr_low;
+
+ switch (msr_index) {
+ case MSR_IA32_FEATURE_CONTROL:
+ *pdata = 0;
+ break;
+ case MSR_IA32_VMX_BASIC:
+ /*
+ * This MSR reports some information about VMX support of the
+ * processor. We should return information about the VMX we
+ * emulate for the guest, and the VMCS structure we give it -
+ * not about the VMX support of the underlying hardware. Some
+ * However, some capabilities of the underlying hardware are
+ * used directly by our emulation (e.g., the physical address
+ * width), so these are copied from what the hardware reports.
+ */
+ *pdata = VMCS12_REVISION |
+ (((u64)sizeof(struct vmcs12))<< 32);
+ rdmsrl(MSR_IA32_VMX_BASIC, vmx_msr);
+#define VMX_BASIC_64 0x0001000000000000LLU
+#define VMX_BASIC_MEM_TYPE 0x003c000000000000LLU
+#define VMX_BASIC_INOUT 0x0040000000000000LLU
Please move those defines (with longer names) to msr-index.h.
+ *pdata |= vmx_msr&
+ (VMX_BASIC_64 | VMX_BASIC_MEM_TYPE | VMX_BASIC_INOUT);
+ break;
+#define CORE2_PINBASED_CTLS_MUST_BE_ONE 0x00000016
+#define MSR_IA32_VMX_TRUE_PINBASED_CTLS 0x48d
+ case MSR_IA32_VMX_TRUE_PINBASED_CTLS:
+ case MSR_IA32_VMX_PINBASED_CTLS:
+ vmx_msr_low = CORE2_PINBASED_CTLS_MUST_BE_ONE;
+ vmx_msr_high = CORE2_PINBASED_CTLS_MUST_BE_ONE |
+ PIN_BASED_EXT_INTR_MASK |
+ PIN_BASED_NMI_EXITING |
+ PIN_BASED_VIRTUAL_NMIS;
IIRC not all processors support PIN_BASED_VIRTUAL_NMIs. Can we support
this feature on hosts that don't have it?
--
error compiling committee.c: too many arguments to function
--
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