Commit 92e64804 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: nVMX: Add a helper to encode VMCS info in MSR_IA32_VMX_BASIC 



Add a helper to encode the VMCS revision, size, and supported memory types
in MSR_IA32_VMX_BASIC, i.e. when synthesizing KVM's supported BASIC MSR
value, and delete the now unused VMCS size and memtype shift macros.

For a variety of reasons, KVM has shifted (pun intended) to using helpers
to *get* information from the VMX MSRs, as opposed to defined MASK and
SHIFT macros for direct use.  Provide a similar helper for the nested VMX
code, which needs to *set* information, so that KVM isn't left with a mix
of SHIFT macros and dedicated helpers.

Reported-by: default avatarXiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: default avatarXiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: default avatarKai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20240605231918.2915961-8-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent c97b106f

arch/x86/include/asm/vmx.h

+5 −2
Original line number Diff line number Diff line
@@ -135,10 +135,8 @@ 
#define VMX_VMFUNC_EPTP_SWITCHING               VMFUNC_CONTROL_BIT(EPTP_SWITCHING)

#define VMFUNC_EPTP_ENTRIES  512



#define VMX_BASIC_VMCS_SIZE_SHIFT		32

#define VMX_BASIC_32BIT_PHYS_ADDR_ONLY		BIT_ULL(48)

#define VMX_BASIC_DUAL_MONITOR_TREATMENT	BIT_ULL(49)

#define VMX_BASIC_MEM_TYPE_SHIFT		50

#define VMX_BASIC_INOUT				BIT_ULL(54)

#define VMX_BASIC_TRUE_CTLS			BIT_ULL(55)
@@ -157,6 +155,11 @@ static inline u32 vmx_basic_vmcs_mem_type(u64 vmx_basic) 
	return (vmx_basic & GENMASK_ULL(53, 50)) >> 50;

}



static inline u64 vmx_basic_encode_vmcs_info(u32 revision, u16 size, u8 memtype)

{

	return revision | ((u64)size << 32) | ((u64)memtype << 50);

}



static inline int vmx_misc_preemption_timer_rate(u64 vmx_misc)

{

	return vmx_misc & VMX_MISC_PREEMPTION_TIMER_RATE_MASK;

arch/x86/kvm/vmx/nested.c

+3 −5
Original line number Diff line number Diff line
@@ -7077,12 +7077,10 @@ static void nested_vmx_setup_basic(struct nested_vmx_msrs *msrs) 
	 * guest, and the VMCS structure we give it - not about the

	 * VMX support of the underlying hardware.

	 */

	msrs->basic =

		VMCS12_REVISION |

		VMX_BASIC_TRUE_CTLS |

		((u64)VMCS12_SIZE << VMX_BASIC_VMCS_SIZE_SHIFT) |

		(X86_MEMTYPE_WB << VMX_BASIC_MEM_TYPE_SHIFT);

	msrs->basic = vmx_basic_encode_vmcs_info(VMCS12_REVISION, VMCS12_SIZE,

						 X86_MEMTYPE_WB);



	msrs->basic |= VMX_BASIC_TRUE_CTLS;

	if (cpu_has_vmx_basic_inout())

		msrs->basic |= VMX_BASIC_INOUT;

}