From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0776EC04FF3 for ; Mon, 24 May 2021 19:55:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D78056140A for ; Mon, 24 May 2021 19:55:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232901AbhEXT5J (ORCPT ); Mon, 24 May 2021 15:57:09 -0400 Received: from smtp-fw-6002.amazon.com ([52.95.49.90]:22668 "EHLO smtp-fw-6002.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232770AbhEXT5I (ORCPT ); Mon, 24 May 2021 15:57:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.de; i=@amazon.de; q=dns/txt; s=amazon201209; t=1621886141; x=1653422141; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=jtPJZRoIcIGMgdID0wVBNd10aPPe6ZAomW4bRSwxqzk=; b=ccLpSd9r09DCNZf3y3ousrZV7i0quQF+3uXeka4IEbQzhcPO8NJoXaUW kDqUE9Jgg1k87zA0xOvAV4cmew7fjxqw4tJRjTlzzd23+qiniGsXJocwT mmrSxTlIK8+aUoIMzblD8G5aiXpk//hIDQjiSB+JYwaCDLJ0nHKx7zsj2 E=; X-IronPort-AV: E=Sophos;i="5.82,325,1613433600"; d="scan'208";a="114312619" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-1d-98acfc19.us-east-1.amazon.com) ([10.43.8.2]) by smtp-border-fw-6002.iad6.amazon.com with ESMTP; 24 May 2021 19:55:40 +0000 Received: from EX13D28EUC003.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-1d-98acfc19.us-east-1.amazon.com (Postfix) with ESMTPS id 292A2A2121; Mon, 24 May 2021 19:55:37 +0000 (UTC) Received: from uc8bbc9586ea454.ant.amazon.com (10.43.161.253) by EX13D28EUC003.ant.amazon.com (10.43.164.43) with Microsoft SMTP Server (TLS) id 15.0.1497.18; Mon, 24 May 2021 19:55:33 +0000 From: Siddharth Chandrasekaran To: Paolo Bonzini , Marcelo Tosatti CC: Siddharth Chandrasekaran , Siddharth Chandrasekaran , Alexander Graf , Evgeny Iakovlev , Liran Alon , Ioannis Aslanidis , , Subject: [PATCH 3/6] kvm/i386: Stop using cpu->kvm_msr_buf in kvm_put_one_msr() Date: Mon, 24 May 2021 21:54:06 +0200 Message-ID: <04c81a02c19a47e799e06b9c9ccb97e9a77f5927.1621885749.git.sidcha@amazon.de> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.43.161.253] X-ClientProxiedBy: EX13D10UWB004.ant.amazon.com (10.43.161.121) To EX13D28EUC003.ant.amazon.com (10.43.164.43) Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org kvm_put_one_msr() zeros cpu->kvm_msr_buf and uses it to set one MSR to KVM. It is pretty wasteful as cpu->kvm_msr_buf is 4096 bytes long; instead use a local buffer to avoid memset. Also, expose this method from kvm_i386.h as hyperv.c needs to set MSRs in a subsequent patch. Signed-off-by: Siddharth Chandrasekaran --- target/i386/kvm/kvm.c | 12 ++++++++---- target/i386/kvm/kvm_i386.h | 1 + 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index d972eb4705..d19a2913fd 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -2534,12 +2534,16 @@ static void kvm_msr_entry_add(X86CPU *cpu, uint32_t index, uint64_t value) msrs->nmsrs++; } -static int kvm_put_one_msr(X86CPU *cpu, int index, uint64_t value) +int kvm_put_one_msr(X86CPU *cpu, int index, uint64_t value) { - kvm_msr_buf_reset(cpu); - kvm_msr_entry_add(cpu, index, value); + uint8_t msr_buf[sizeof(struct kvm_msrs) + sizeof(struct kvm_msr_entry)] = { 0 }; + struct kvm_msrs *msr = (struct kvm_msrs *)msr_buf; + + msr->nmsrs = 1; + msr->entries[0].index = index; + msr->entries[0].data = value; - return kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MSRS, cpu->kvm_msr_buf); + return kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MSRS, msr); } void kvm_put_apicbase(X86CPU *cpu, uint64_t value) diff --git a/target/i386/kvm/kvm_i386.h b/target/i386/kvm/kvm_i386.h index dc72508389..0c4cd08071 100644 --- a/target/i386/kvm/kvm_i386.h +++ b/target/i386/kvm/kvm_i386.h @@ -40,6 +40,7 @@ void kvm_synchronize_all_tsc(void); void kvm_arch_reset_vcpu(X86CPU *cs); void kvm_arch_do_init_vcpu(X86CPU *cs); +int kvm_put_one_msr(X86CPU *cpu, int index, uint64_t value); void kvm_put_apicbase(X86CPU *cpu, uint64_t value); bool kvm_enable_x2apic(void); -- 2.17.1 Amazon Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B Sitz: Berlin Ust-ID: DE 289 237 879