From patchwork Tue Jun 16 21:50:51 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mario Smarduch X-Patchwork-Id: 6620621 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id CF34A9F52D for ; Tue, 16 Jun 2015 21:53:59 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9BB7320802 for ; Tue, 16 Jun 2015 21:53:57 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B1EA020801 for ; Tue, 16 Jun 2015 21:53:56 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Z4ylr-0005ms-Vt; Tue, 16 Jun 2015 21:51:51 +0000 Received: from mailout1.w2.samsung.com ([211.189.100.11] helo=usmailout1.samsung.com) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Z4ylg-0005jn-Ix for linux-arm-kernel@lists.infradead.org; Tue, 16 Jun 2015 21:51:41 +0000 Received: from uscpsbgex4.samsung.com (u125.gpu85.samsung.co.kr [203.254.195.125]) by mailout1.w2.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0NQ200HTZ4PZKL30@mailout1.w2.samsung.com> for linux-arm-kernel@lists.infradead.org; Tue, 16 Jun 2015 17:51:35 -0400 (EDT) X-AuditID: cbfec37d-f79746d0000068cf-a9-55809a675414 Received: from usmmp2.samsung.com ( [203.254.195.78]) by uscpsbgex4.samsung.com (USCPEXMTA) with SMTP id AD.15.26831.76A90855; Tue, 16 Jun 2015 17:51:35 -0400 (EDT) Received: from sisasmtp.sisa.samsung.com ([105.144.21.116]) by usmmp2.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0NQ2001C74PYG630@usmmp2.samsung.com>; Tue, 16 Jun 2015 17:51:35 -0400 (EDT) Received: from mjsmard-530U3C-530U4C-532U3C.sisa.samsung.com (105.145.24.31) by SISAEX02SJ.sisa.samsung.com (105.144.21.116) with Microsoft SMTP Server (TLS) id 14.3.224.2; Tue, 16 Jun 2015 14:51:34 -0700 From: Mario Smarduch To: kvmarm@lists.cs.columbia.edu, marc.zyngier@arm.com, christoffer.dall@linaro.org Subject: [PATCH v2 1/2] arm64: KVM: Optimize arm64 fp/simd save/restore Date: Tue, 16 Jun 2015 14:50:51 -0700 Message-id: <1434491452-19177-2-git-send-email-m.smarduch@samsung.com> X-Mailer: git-send-email 1.7.9.5 In-reply-to: <1434491452-19177-1-git-send-email-m.smarduch@samsung.com> References: <1434491452-19177-1-git-send-email-m.smarduch@samsung.com> MIME-version: 1.0 X-Originating-IP: [105.145.24.31] X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrCLMWRmVeSWpSXmKPExsVy+t9hP930WQ2hBn9mSVq8X9bDaPHi9T9G izlTCy0+njrObrHp8TVWi793/rFZvPx4gsWB3WPNvDWMHneu7WHzOL9pDbPH5iX1Hp83yQWw RnHZpKTmZJalFunbJXBlTNm0nb3gq0zF8YOpDYzXxLoYOTkkBEwk2n8eY4ewxSQu3FvP1sXI xSEksIxRYtH5/YwQThOTxJo785ghnAuMEt+fbmIBaWET0JXYf28jWLuIQKjE9b+NTCA2s8AM RonW1jwQW1jAXWL5nA/MIDaLgKpE28P1YL28Am4SF3p2A9kcQKsVJOZMsgEJcwKVN9xcCzZS CKhk2s/fjBDlghI/Jt8DK2cWkJB4/lkJokRVYtvN54wQDyhK3Do/n2kCo9AsJB2zEDoWMDKt YhQrLU4uKE5KT60w0StOzC0uzUvXS87P3cQICfvaHYz3v9ocYhTgYFTi4Z1h3hAqxJpYVlyZ e4hRgoNZSYQ3fDJQiDclsbIqtSg/vqg0J7X4EKM0B4uSOG+EpFyokEB6YklqdmpqQWoRTJaJ g1OqgXHNsVjdeYv0XctrlKaorQ5yuN3ya7+xSdqaxlnct62lhKseMHZscjW4snjm0U03lr1+ drpL7cO2HNcXq/xnBBsvEZmfdCy/i2W9ZHLuoRt/GFkP1L3cd9blZU7s27Qr1+5+nXZzp9Xk Q3++PJ34+dzkfVOCD6YxXpJgjmy6dtUp8DlLh+3nk298lViKMxINtZiLihMBbmGjUXcCAAA= X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150616_145140_724032_182339A9 X-CRM114-Status: UNSURE ( 9.11 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -5.7 (-----) Cc: catalin.marinas@arm.com, will.deacon@arm.com, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Mario Smarduch X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.8 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch only saves and restores FP/SIMD registers on Guest access. To do this cptr_el2 FP/SIMD trap is set on Guest entry and later checked on exit. lmbench, hackbench show significant improvements, for 30-50% exits FP/SIMD context is not saved/restored Signed-off-by: Mario Smarduch Reviewed-by: Marc Zyngier --- arch/arm64/include/asm/kvm_arm.h | 5 ++++- arch/arm64/kvm/hyp.S | 46 +++++++++++++++++++++++++++++++++++--- 2 files changed, 47 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index ac6fafb..7605e09 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -171,10 +171,13 @@ #define HSTR_EL2_TTEE (1 << 16) #define HSTR_EL2_T(x) (1 << x) +/* Hyp Coproccessor Trap Register Shifts */ +#define CPTR_EL2_TFP_SHIFT 10 + /* Hyp Coprocessor Trap Register */ #define CPTR_EL2_TCPAC (1 << 31) #define CPTR_EL2_TTA (1 << 20) -#define CPTR_EL2_TFP (1 << 10) +#define CPTR_EL2_TFP (1 << CPTR_EL2_TFP_SHIFT) /* Hyp Debug Configuration Register bits */ #define MDCR_EL2_TDRA (1 << 11) diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index 5befd01..de0788f 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -673,6 +673,15 @@ tbz \tmp, #KVM_ARM64_DEBUG_DIRTY_SHIFT, \target .endm +/* + * Check cptr VFP/SIMD accessed bit, if set VFP/SIMD not accessed by guest. + */ +.macro skip_fpsimd_state tmp, target + mrs \tmp, cptr_el2 + tbnz \tmp, #CPTR_EL2_TFP_SHIFT, \target +.endm + + .macro compute_debug_state target // Compute debug state: If any of KDE, MDE or KVM_ARM64_DEBUG_DIRTY // is set, we do a full save/restore cycle and disable trapping. @@ -763,6 +772,7 @@ ldr x2, [x0, #VCPU_HCR_EL2] msr hcr_el2, x2 mov x2, #CPTR_EL2_TTA + orr x2, x2, #CPTR_EL2_TFP msr cptr_el2, x2 mov x2, #(1 << 15) // Trap CP15 Cr=15 @@ -785,7 +795,6 @@ .macro deactivate_traps mov x2, #HCR_RW msr hcr_el2, x2 - msr cptr_el2, xzr msr hstr_el2, xzr mrs x2, mdcr_el2 @@ -912,6 +921,28 @@ __restore_fpsimd: restore_fpsimd ret +switch_to_guest_fpsimd: + push x4, lr + + mrs x2, cptr_el2 + bic x2, x2, #CPTR_EL2_TFP + msr cptr_el2, x2 + + mrs x0, tpidr_el2 + + ldr x2, [x0, #VCPU_HOST_CONTEXT] + kern_hyp_va x2 + bl __save_fpsimd + + add x2, x0, #VCPU_CONTEXT + bl __restore_fpsimd + + pop x4, lr + pop x2, x3 + pop x0, x1 + + eret + /* * u64 __kvm_vcpu_run(struct kvm_vcpu *vcpu); * @@ -932,7 +963,6 @@ ENTRY(__kvm_vcpu_run) kern_hyp_va x2 save_host_regs - bl __save_fpsimd bl __save_sysregs compute_debug_state 1f @@ -948,7 +978,6 @@ ENTRY(__kvm_vcpu_run) add x2, x0, #VCPU_CONTEXT bl __restore_sysregs - bl __restore_fpsimd skip_debug_state x3, 1f bl __restore_debug @@ -967,7 +996,9 @@ __kvm_vcpu_return: add x2, x0, #VCPU_CONTEXT save_guest_regs + skip_fpsimd_state x3, 1f bl __save_fpsimd +1: bl __save_sysregs skip_debug_state x3, 1f @@ -986,7 +1017,11 @@ __kvm_vcpu_return: kern_hyp_va x2 bl __restore_sysregs + skip_fpsimd_state x3, 1f bl __restore_fpsimd +1: + /* Clear FPSIMD and Trace trapping */ + msr cptr_el2, xzr skip_debug_state x3, 1f // Clear the dirty flag for the next run, as all the state has @@ -1201,6 +1236,11 @@ el1_trap: * x1: ESR * x2: ESR_EC */ + + /* Guest accessed VFP/SIMD registers, save host, restore Guest */ + cmp x2, #ESR_ELx_EC_FP_ASIMD + b.eq switch_to_guest_fpsimd + cmp x2, #ESR_ELx_EC_DABT_LOW mov x0, #ESR_ELx_EC_IABT_LOW ccmp x2, x0, #4, ne