linux-kernel - [PATCH v6 02/33] x86/hyperv: Update 'struct hv_enlightened

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Message-Id: <20220830133737.1539624-3-vkuznets@redhat.com>
Date:   Tue, 30 Aug 2022 15:37:06 +0200
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     kvm@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Michael Kelley <mikelley@...rosoft.com>,
        Yuan Yao <yuan.yao@...ux.intel.com>,
        Maxim Levitsky <mlevitsk@...hat.com>,
        linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v6 02/33] x86/hyperv: Update 'struct hv_enlightened_vmcs' definition

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 <vkuznets@...hat.com>
[sean: tweak CPUID name to make it PerfGlobalCtrl only]
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/include/asm/hyperv-tlfs.h | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index 6f0acc45e67a..3089ec352743 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -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
@@ -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
-- 
2.37.2