linux-kernel - [PATCH 35/43] KVM: x86: Move setting of sregs during vCPU RESET/INIT to common x86

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Date:   Fri, 23 Apr 2021 17:46:37 -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
Subject: [PATCH 35/43] 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 between 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.

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 996a6b03e338..23f880268ff5 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1204,12 +1204,6 @@ 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 8c982e049cbb..d8afca144e11 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4557,9 +4557,6 @@ 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);
 
@@ -4587,12 +4584,6 @@ 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 167c650d1187..97d8e3e74bab 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10499,6 +10499,14 @@ 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);
+
 	if (kvm_cr0_mmu_role_changed(old_cr0, kvm_read_cr0(vcpu)) ||
 	    kvm_cr4_mmu_role_changed(old_cr4, kvm_read_cr4(vcpu)))
 		kvm_mmu_reset_context(vcpu);
-- 
2.31.1.498.g6c1eba8ee3d-goog