From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk1-f195.google.com ([209.85.222.195]:37235 "EHLO mail-qk1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727958AbeKHCPb (ORCPT ); Wed, 7 Nov 2018 21:15:31 -0500 Received: by mail-qk1-f195.google.com with SMTP id 131so21772134qkd.4 for ; Wed, 07 Nov 2018 08:44:22 -0800 (PST) From: David Long To: stable@vger.kernel.org, Russell King - ARM Linux , Florian Fainelli , Tony Lindgren , Marc Zyngier , Mark Rutland Cc: Greg KH , Mark Brown Subject: [PATCH 4.9 V2 14/24] ARM: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling Date: Wed, 7 Nov 2018 11:43:52 -0500 Message-Id: <20181107164402.9380-15-dave.long@linaro.org> In-Reply-To: <20181107164402.9380-1-dave.long@linaro.org> References: <20181107164402.9380-1-dave.long@linaro.org> Sender: stable-owner@vger.kernel.org List-ID: From: Russell King 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 Boot-tested-by: Tony Lindgren Reviewed-by: Tony Lindgren Reviewed-by: Marc Zyngier Signed-off-by: David A. Long --- arch/arm/kvm/hyp/hyp-entry.S | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) 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 #include #include #include @@ -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 -- 2.17.1