linux-kernel - [PATCH 15/17] KVM: retpolines: x86: eliminate retpoline from vmx.c exit handlers

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190920212509.2578-16-aarcange@redhat.com>
Date:   Fri, 20 Sep 2019 17:25:07 -0400
From:   Andrea Arcangeli <aarcange@...hat.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Vitaly Kuznetsov <vkuznets@...hat.com>,
        "Dr. David Alan Gilbert" <dgilbert@...hat.com>,
        Marcelo Tosatti <mtosatti@...hat.com>,
        Peter Xu <peterx@...hat.com>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 15/17] KVM: retpolines: x86: eliminate retpoline from vmx.c exit handlers

It's enough to check the exit value and issue a direct call to avoid
the retpoline for all the common vmexit reasons.

Signed-off-by: Andrea Arcangeli <aarcange@...hat.com>
---
 arch/x86/kvm/vmx/vmx.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index a6e597025011..9aa73e216df2 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5866,9 +5866,29 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu)
 	}
 
 	if (exit_reason < kvm_vmx_max_exit_handlers
-	    && kvm_vmx_exit_handlers[exit_reason])
+	    && kvm_vmx_exit_handlers[exit_reason]) {
+#ifdef CONFIG_RETPOLINE
+		if (exit_reason == EXIT_REASON_MSR_WRITE)
+			return handle_wrmsr(vcpu);
+		else if (exit_reason == EXIT_REASON_PREEMPTION_TIMER)
+			return handle_preemption_timer(vcpu);
+		else if (exit_reason == EXIT_REASON_PENDING_INTERRUPT)
+			return handle_interrupt_window(vcpu);
+		else if (exit_reason == EXIT_REASON_EXTERNAL_INTERRUPT)
+			return handle_external_interrupt(vcpu);
+		else if (exit_reason == EXIT_REASON_HLT)
+			return handle_halt(vcpu);
+		else if (exit_reason == EXIT_REASON_PAUSE_INSTRUCTION)
+			return handle_pause(vcpu);
+		else if (exit_reason == EXIT_REASON_MSR_READ)
+			return handle_rdmsr(vcpu);
+		else if (exit_reason == EXIT_REASON_CPUID)
+			return handle_cpuid(vcpu);
+		else if (exit_reason == EXIT_REASON_EPT_MISCONFIG)
+			return handle_ept_misconfig(vcpu);
+#endif
 		return kvm_vmx_exit_handlers[exit_reason](vcpu);
-	else {
+	} else {
 		vcpu_unimpl(vcpu, "vmx: unexpected exit reason 0x%x\n",
 				exit_reason);
 		dump_vmcs();