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x86/hyperv: Update 'struct hv_enlightened_vmcs' definition
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Updated Hyper-V Enlightened VMCS specification lists several new
fields for the following features:

- PerfGlobalCtrl
- EnclsExitingBitmap
- Tsc Scaling
- GuestLbrCtl
- CET
- SSP

Update the definition.

Note, the updated spec also provides an additional CPUID feature flag,
CPUIDD.0x4000000A.EBX BIT(0), for PerfGlobalCtrl to workaround a Windows
11 quirk.  Despite what the TLFS says:

  Indicates support for the GuestPerfGlobalCtrl and HostPerfGlobalCtrl
  fields in the enlightened VMCS.

guests can safely use the fields if they are enumerated in the
architectural VMX MSRs.  I.e. KVM-on-HyperV doesn't need to check the
CPUID bit, but KVM-as-HyperV must ensure the bit is set if PerfGlobalCtrl
fields are exposed to L1.

https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/tlfs

Signed-off-by: Vitaly Kuznetsov <[email protected]>
[sean: tweak CPUID name to make it PerfGlobalCtrl only]
Signed-off-by: Sean Christopherson <[email protected]>
Acked-by: Wei Liu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Bonzini <[email protected]>
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vittyvk authored and bonzini committed Sep 26, 2022
1 parent ea9da78 commit 5ef384a
Showing 1 changed file with 16 additions and 2 deletions.
18 changes: 16 additions & 2 deletions arch/x86/include/asm/hyperv-tlfs.h
Original file line number Diff line number Diff line change
Expand Up @@ -138,6 +138,9 @@
#define HV_X64_NESTED_GUEST_MAPPING_FLUSH BIT(18)
#define HV_X64_NESTED_MSR_BITMAP BIT(19)

/* Nested features #2. These are HYPERV_CPUID_NESTED_FEATURES.EBX bits. */
#define HV_X64_NESTED_EVMCS1_PERF_GLOBAL_CTRL BIT(0)

/*
* This is specific to AMD and specifies that enlightened TLB flush is
* supported. If guest opts in to this feature, ASID invalidations only
Expand Down Expand Up @@ -559,9 +562,20 @@ struct hv_enlightened_vmcs {
u64 partition_assist_page;
u64 padding64_4[4];
u64 guest_bndcfgs;
u64 padding64_5[7];
u64 guest_ia32_perf_global_ctrl;
u64 guest_ia32_s_cet;
u64 guest_ssp;
u64 guest_ia32_int_ssp_table_addr;
u64 guest_ia32_lbr_ctl;
u64 padding64_5[2];
u64 xss_exit_bitmap;
u64 padding64_6[7];
u64 encls_exiting_bitmap;
u64 host_ia32_perf_global_ctrl;
u64 tsc_multiplier;
u64 host_ia32_s_cet;
u64 host_ssp;
u64 host_ia32_int_ssp_table_addr;
u64 padding64_6;
} __packed;

#define HV_VMX_ENLIGHTENED_CLEAN_FIELD_NONE 0
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