[PATCH 4.14 099/109] ARM: KVM: report support for SMCCC_ARCH_WORKAROUND_1

Greg Kroah-Hartman
2018-10-16T17:21:42Z

From: Russell King <rmk+kernel@armlinux.org.uk>

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>
---
arch/arm/include/asm/kvm_host.h | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)

--- 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 kv

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