From: Russell King <rmk+kernel@armlinux.org.uk>
Date: Mon, 15 Oct 2018 15:32:09 +0000 (-0400)
Subject: ARM: KVM: report support for SMCCC_ARCH_WORKAROUND_1
X-Git-Tag: v4.14.77~11
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e7fc401a8800b9d657e2d1ba7188592b449c9c84;p=platform%2Fkernel%2Flinux-exynos.git

ARM: KVM: report support for SMCCC_ARCH_WORKAROUND_1

Commit add5609877c6785cc002c6ed7e008b1d61064439 upstream.

Report support for SMCCC_ARCH_WORKAROUND_1 to KVM guests for affected
CPUs.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 65572e14306c..b60232639984 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -21,6 +21,7 @@
 
 #include <linux/types.h>
 #include <linux/kvm_types.h>
+#include <asm/cputype.h>
 #include <asm/kvm.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_mmio.h>
@@ -298,8 +299,17 @@ int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu,
 
 static inline bool kvm_arm_harden_branch_predictor(void)
 {
-	/* No way to detect it yet, pretend it is not there. */
-	return false;
+	switch(read_cpuid_part()) {
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+	case ARM_CPU_PART_BRAHMA_B15:
+	case ARM_CPU_PART_CORTEX_A12:
+	case ARM_CPU_PART_CORTEX_A15:
+	case ARM_CPU_PART_CORTEX_A17:
+		return true;
+#endif
+	default:
+		return false;
+	}
 }
 
 #define KVM_SSBD_UNKNOWN		-1