linux-kernel - [PATCH 10/15] KVM: x86: Use KVM_REQ_TLB_FLUSH

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Message-Id: <20210609234235.1244004-11-seanjc@google.com>
Date:   Wed,  9 Jun 2021 16:42:30 -0700
From:   Sean Christopherson <seanjc@...gle.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Junaid Shahid <junaids@...gle.com>,
        Maxim Levitsky <mlevitsk@...hat.com>,
        Lai Jiangshan <laijs@...ux.alibaba.com>
Subject: [PATCH 10/15] KVM: x86: Use KVM_REQ_TLB_FLUSH_GUEST to handle
 INVPCID(ALL) emulation

Use KVM_REQ_TLB_FLUSH_GUEST instead of KVM_REQ_MMU_RELOAD when emulating
INVPCID of all contexts.  In the current code, this is a glorified nop as
TLB_FLUSH_GUEST becomes kvm_mmu_unload(), same as MMU_RELOAD, when TDP
is disabled, which is the only time INVPCID is only intercepted+emulated.
In the future, reusing TLB_FLUSH_GUEST will simplify optimizing paths
that emulate a guest TLB flush, e.g. by synchronizing as needed instead
of completely unloading all MMUs.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/x86.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 117acfbc7ba9..9620d8936dc4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11776,7 +11776,7 @@ int kvm_handle_invpcid(struct kvm_vcpu *vcpu, unsigned long type, gva_t gva)
 
 		fallthrough;
 	case INVPCID_TYPE_ALL_INCL_GLOBAL:
-		kvm_make_request(KVM_REQ_MMU_RELOAD, vcpu);
+		kvm_make_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu);
 		return kvm_skip_emulated_instruction(vcpu);
 
 	default:
-- 
2.32.0.rc1.229.g3e70b5a671-goog