linux-kernel - [PATCH v3 1/6] KVM: SVM: split svm_handle_invalid

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Message-Id: <20210811122927.900604-2-mlevitsk@redhat.com>
Date:   Wed, 11 Aug 2021 15:29:22 +0300
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     kvm@...r.kernel.org
Cc:     Kieran Bingham <kbingham@...nel.org>,
        Jan Kiszka <jan.kiszka@...mens.com>,
        Andrew Jones <drjones@...hat.com>,
        Jonathan Corbet <corbet@....net>,
        Maxim Levitsky <mlevitsk@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Ingo Molnar <mingo@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        x86@...nel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
        Johannes Berg <johannes.berg@...el.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        "H. Peter Anvin" <hpa@...or.com>, Jessica Yu <jeyu@...nel.org>,
        Jim Mattson <jmattson@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Joerg Roedel <joro@...tes.org>,
        Yang Weijiang <weijiang.yang@...el.com>,
        linux-kernel@...r.kernel.org, Borislav Petkov <bp@...en8.de>,
        linux-kselftest@...r.kernel.org (open list:KERNEL SELFTEST FRAMEWORK),
        linux-doc@...r.kernel.org (open list:DOCUMENTATION),
        Shuah Khan <shuah@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>
Subject: [PATCH v3 1/6] KVM: SVM: split svm_handle_invalid_exit

Split the check for having a vmexit handler to svm_check_exit_valid,
and make svm_handle_invalid_exit only handle a vmexit that is
already not valid.

Signed-off-by: Maxim Levitsky <mlevitsk@...hat.com>
---
 arch/x86/kvm/svm/svm.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 7b58e445a967..e45259177009 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3236,12 +3236,14 @@ static void dump_vmcb(struct kvm_vcpu *vcpu)
 	       "excp_to:", save->last_excp_to);
 }
 
-static int svm_handle_invalid_exit(struct kvm_vcpu *vcpu, u64 exit_code)
+static bool svm_check_exit_valid(struct kvm_vcpu *vcpu, u64 exit_code)
 {
-	if (exit_code < ARRAY_SIZE(svm_exit_handlers) &&
-	    svm_exit_handlers[exit_code])
-		return 0;
+	return (exit_code < ARRAY_SIZE(svm_exit_handlers) &&
+		svm_exit_handlers[exit_code]);
+}
 
+static int svm_handle_invalid_exit(struct kvm_vcpu *vcpu, u64 exit_code)
+{
 	vcpu_unimpl(vcpu, "svm: unexpected exit reason 0x%llx\n", exit_code);
 	dump_vmcb(vcpu);
 	vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
@@ -3249,14 +3251,13 @@ static int svm_handle_invalid_exit(struct kvm_vcpu *vcpu, u64 exit_code)
 	vcpu->run->internal.ndata = 2;
 	vcpu->run->internal.data[0] = exit_code;
 	vcpu->run->internal.data[1] = vcpu->arch.last_vmentry_cpu;
-
-	return -EINVAL;
+	return 0;
 }
 
 int svm_invoke_exit_handler(struct kvm_vcpu *vcpu, u64 exit_code)
 {
-	if (svm_handle_invalid_exit(vcpu, exit_code))
-		return 0;
+	if (!svm_check_exit_valid(vcpu, exit_code))
+		return svm_handle_invalid_exit(vcpu, exit_code);
 
 #ifdef CONFIG_RETPOLINE
 	if (exit_code == SVM_EXIT_MSR)
-- 
2.26.3