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authorRussell King <rmk+kernel@armlinux.org.uk>2018-11-07 11:43:52 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-11-23 08:20:38 +0100
commitb8940544118bdcab5da92ca76f527784cab882ce (patch)
tree7c6d1bbdcfce0d2db0a3b63786d4e22e1d083764 /arch/arm/kvm
parent10c7b397cf5d35bdaf8a99a0e0dc4f02fdd05118 (diff)
ARM: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling
Commit b800acfc70d9fb81fbd6df70f2cf5e20f70023d0 upstream. We want SMCCC_ARCH_WORKAROUND_1 to be fast. As fast as possible. So let's intercept it as early as we can by testing for the function call number as soon as we've identified a HVC call coming from the guest. 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>
Diffstat (limited to 'arch/arm/kvm')
-rw-r--r--arch/arm/kvm/hyp/hyp-entry.S17
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S
index 1bdd03014138..64d4a39f4b4b 100644
--- a/arch/arm/kvm/hyp/hyp-entry.S
+++ b/arch/arm/kvm/hyp/hyp-entry.S
@@ -16,6 +16,7 @@
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
+#include <linux/arm-smccc.h>
#include <linux/linkage.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
@@ -202,7 +203,7 @@ hyp_hvc:
lsr r2, r2, #16
and r2, r2, #0xff
cmp r2, #0
- bne guest_trap @ Guest called HVC
+ bne guest_hvc_trap @ Guest called HVC
/*
* Getting here means host called HVC, we shift parameters and branch
@@ -235,6 +236,20 @@ THUMB( orr lr, #1)
pop {r2, lr}
1: eret
+guest_hvc_trap:
+ movw r2, #:lower16:ARM_SMCCC_ARCH_WORKAROUND_1
+ movt r2, #:upper16:ARM_SMCCC_ARCH_WORKAROUND_1
+ ldr r0, [sp] @ Guest's r0
+ teq r0, r2
+ bne guest_trap
+ add sp, sp, #12
+ @ Returns:
+ @ r0 = 0
+ @ r1 = HSR value (perfectly predictable)
+ @ r2 = ARM_SMCCC_ARCH_WORKAROUND_1
+ mov r0, #0
+ eret
+
guest_trap:
load_vcpu r0 @ Load VCPU pointer to r0