linux-kernel - [PATCH v2 36/46] KVM: x86: Move setting of sregs during vCPU RESET/INIT to common x86

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Date:   Tue, 13 Jul 2021 09:33:14 -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, Reiji Watanabe <reijiw@...gle.com>
Subject: [PATCH v2 36/46] KVM: x86: Move setting of sregs during vCPU
 RESET/INIT to common x86

Move the setting of CR0, CR4, EFER, RFLAGS, and RIP from vendor code to
common x86.  VMX and SVM now have near-identical sequences, the only
difference being that VMX updates the exception bitmap.  Updating the
bitmap on SVM is unnecessary, but benign.  Unfortunately it can't be left
behind in VMX due to the need to update exception intercepts after the
control registers are set.

Reviewed-by: Reiji Watanabe <reijiw@...gle.com>
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/svm/svm.c | 6 ------
 arch/x86/kvm/vmx/vmx.c | 9 ---------
 arch/x86/kvm/x86.c     | 8 ++++++++
 3 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 251b230b2fef..ea4bea428078 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1262,12 +1262,6 @@ static void init_vmcb(struct kvm_vcpu *vcpu)
 	init_sys_seg(&save->ldtr, SEG_TYPE_LDT);
 	init_sys_seg(&save->tr, SEG_TYPE_BUSY_TSS16);
 
-	svm_set_cr0(vcpu, X86_CR0_NW | X86_CR0_CD | X86_CR0_ET);
-	svm_set_cr4(vcpu, 0);
-	svm_set_efer(vcpu, 0);
-	kvm_set_rflags(vcpu, X86_EFLAGS_FIXED);
-	vcpu->arch.regs[VCPU_REGS_RIP] = 0x0000fff0;
-
 	if (npt_enabled) {
 		/* Setup VMCB for Nested Paging */
 		control->nested_ctl |= SVM_NESTED_CTL_NP_ENABLE;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 555235d6c17e..ef92ec40d3d9 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4454,9 +4454,6 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
 		vmcs_write64(GUEST_IA32_DEBUGCTL, 0);
 	}
 
-	kvm_set_rflags(vcpu, X86_EFLAGS_FIXED);
-	kvm_rip_write(vcpu, 0xfff0);
-
 	vmcs_writel(GUEST_GDTR_BASE, 0);
 	vmcs_write32(GUEST_GDTR_LIMIT, 0xffff);
 
@@ -4484,12 +4481,6 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
 
 	kvm_make_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu);
 
-	vmx_set_cr0(vcpu, X86_CR0_NW | X86_CR0_CD | X86_CR0_ET);
-	vmx_set_cr4(vcpu, 0);
-	vmx_set_efer(vcpu, 0);
-
-	vmx_update_exception_bitmap(vcpu);
-
 	vpid_sync_context(vmx->vpid);
 	if (init_event)
 		vmx_clear_hlt(vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6a11ec5d38ac..3aa952edd5f4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10870,6 +10870,14 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
 
 	static_call(kvm_x86_vcpu_reset)(vcpu, init_event);
 
+	kvm_set_rflags(vcpu, X86_EFLAGS_FIXED);
+	kvm_rip_write(vcpu, 0xfff0);
+
+	static_call(kvm_x86_set_cr0)(vcpu, X86_CR0_NW | X86_CR0_CD | X86_CR0_ET);
+	static_call(kvm_x86_set_cr4)(vcpu, 0);
+	static_call(kvm_x86_set_efer)(vcpu, 0);
+	static_call(kvm_x86_update_exception_bitmap)(vcpu);
+
 	/*
 	 * Reset the MMU context if paging was enabled prior to INIT (which is
 	 * implied if CR0.PG=1 as CR0 will be '0' prior to RESET).  Unlike the
-- 
2.32.0.93.g670b81a890-goog