From patchwork Mon Nov 18 01:09:07 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: pingfan liu X-Patchwork-Id: 291919 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [IPv6:::1]) by ozlabs.org (Postfix) with ESMTP id B44D22C0357 for ; Mon, 18 Nov 2013 12:08:50 +1100 (EST) Received: from mail-ob0-x22e.google.com (mail-ob0-x22e.google.com [IPv6:2607:f8b0:4003:c01::22e]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 518CA2C0090 for ; Mon, 18 Nov 2013 12:08:26 +1100 (EST) Received: by mail-ob0-f174.google.com with SMTP id uy5so6226966obc.5 for ; Sun, 17 Nov 2013 17:08:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=EbHH1SAs0NPiRsazi7fnVCicB2DYMMu2R7iBgHLo0VA=; b=B2ptBDWuteS30HIWfkFrJiiVTnau4494SgRlWQedHMLNmmqfGRKe2FCXoQbdp9d9ro 7Sz4Kys3KhvPNiLRuOxFiRMDC1QPLkQ5LxVmzNUeJ33+51WfFD3eGGdizdxlMJsR2cri 08Yu4RG9SvFeOVMBnMGT84XsSBvtsq83uF9jet8t9hcCFBI9CHQdw9VsfGJF//lrG6nn /nB+cqZe/og4Ah5vgq0i/diot4lpmGzlvhGPCWti6xSu1NQNvYS8TM0viDbq7jtmp9iG frmzQNSej3UWImlFYBCPe6sXw3HxFdmKADoc6rTVzsNQaSvANVH3zH6slDbZnJp9lb3G BzBA== X-Received: by 10.182.28.134 with SMTP id b6mr17742958obh.27.1384736902492; Sun, 17 Nov 2013 17:08:22 -0800 (PST) Received: from localhost ([202.108.130.138]) by mx.google.com with ESMTPSA id r3sm25031763oep.2.2013.11.17.17.08.20 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Sun, 17 Nov 2013 17:08:21 -0800 (PST) From: Liu Ping Fan To: linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org Subject: [PATCH v3] powerpc: kvm: optimize "sc 1" as fast return Date: Mon, 18 Nov 2013 09:09:07 +0800 Message-Id: <1384736947-21437-1-git-send-email-pingfank@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.1.4 Cc: Paul Mackerras , Alexander Graf X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.16rc2 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" In some scene, e.g openstack CI, PR guest can trigger "sc 1" frequently, this patch optimizes the path by directly delivering BOOK3S_INTERRUPT_SYSCALL to HV guest, so powernv can return to HV guest without heavy exit, i.e, no need to swap TLB, HTAB,.. etc Signed-off-by: Liu Ping Fan --- arch/powerpc/kvm/book3s_hv.c | 6 ------ arch/powerpc/kvm/book3s_hv_rmhandlers.S | 12 +++++++++++- 2 files changed, 11 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 62a2b5a..73dc852 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -628,12 +628,6 @@ static int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu, /* hcall - punt to userspace */ int i; - if (vcpu->arch.shregs.msr & MSR_PR) { - /* sc 1 from userspace - reflect to guest syscall */ - kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_SYSCALL); - r = RESUME_GUEST; - break; - } run->papr_hcall.nr = kvmppc_get_gpr(vcpu, 3); for (i = 0; i < 9; ++i) run->papr_hcall.args[i] = kvmppc_get_gpr(vcpu, 4 + i); diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index c71103b..0d1e2c2 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -1388,7 +1388,8 @@ kvmppc_hisi: hcall_try_real_mode: ld r3,VCPU_GPR(R3)(r9) andi. r0,r11,MSR_PR - bne guest_exit_cont + /* sc 1 from userspace - reflect to guest syscall */ + bne sc_1_fast_return clrrdi r3,r3,2 cmpldi r3,hcall_real_table_end - hcall_real_table bge guest_exit_cont @@ -1409,6 +1410,15 @@ hcall_try_real_mode: ld r11,VCPU_MSR(r4) b fast_guest_return +sc_1_fast_return: + mtspr SPRN_SRR0,r10 + mtspr SPRN_SRR1,r11 + li r10, BOOK3S_INTERRUPT_SYSCALL + li r11, (MSR_ME << 1) | 1 /* synthesize MSR_SF | MSR_ME */ + rotldi r11, r11, 63 + mr r4,r9 + b fast_guest_return + /* We've attempted a real mode hcall, but it's punted it back * to userspace. We need to restore some clobbered volatiles * before resuming the pass-it-to-qemu path */