linux-kernel - [PATCH v2 25/30] KVM: x86: hyper-v: Honor HV_X64_REMOTE_TLB_FLUSH

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Date:   Fri, 21 May 2021 11:51:59 +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>,
        Siddharth Chandrasekaran <sidcha@...zon.de>,
        linux-kernel@...r.kernel.org
Subject: [PATCH v2 25/30] KVM: x86: hyper-v: Honor HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED bit

Hyper-V partition must possess 'HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED'
privilege ('recommended' is rather a misnomer) to issue
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST/SPACE hypercalls.

Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
---
 arch/x86/kvm/hyperv.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 36ec688cda4e..f99072e092d0 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -2044,6 +2044,12 @@ static bool hv_check_hypercall_access(struct kvm_vcpu_hv *hv_vcpu, u16 code)
 		 */
 		return !kvm_hv_is_syndbg_enabled(hv_vcpu->vcpu) ||
 			hv_vcpu->cpuid_cache.features_ebx & HV_DEBUGGING;
+	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
+	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
+	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
+	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
+		return hv_vcpu->cpuid_cache.enlightenments_eax &
+			HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
 	default:
 		break;
 	}
-- 
2.31.1