From nobody Tue Sep 16 21:49:15 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D9DCC4332F for ; Wed, 28 Dec 2022 19:25:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233642AbiL1TZ1 (ORCPT ); Wed, 28 Dec 2022 14:25:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46530 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233350AbiL1TZF (ORCPT ); Wed, 28 Dec 2022 14:25:05 -0500 Received: from mail-pj1-x1049.google.com (mail-pj1-x1049.google.com [IPv6:2607:f8b0:4864:20::1049]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E32AB183AE for ; Wed, 28 Dec 2022 11:24:56 -0800 (PST) Received: by mail-pj1-x1049.google.com with SMTP id v16-20020a17090a899000b00219b1f0ddebso12926757pjn.5 for ; Wed, 28 Dec 2022 11:24:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=sIyfuO6L8HnU8CmCldKrIpDi7aTZJyxJfn1wljTzIeI=; b=HbphtqtIjGcu1bCKK6wFWu4E/GlYZGDlsYger0IgbCeUkoHRrvjgvwYnY/vOQNJS3v FyjI7bdMglfCpRTTsNvK49p8IyLNoVRBVdcnldRVB+HUTo08LKiSrhC5Q/0Uc+QQdp+X IHJ89MTp65CrwucYaVMtjMiROhNdBnnGYlBREUmDHiQkTkehUA4DlpRUBvud1+SVqpMC 6jKDiAXw31yGNOiO07z1YlMzIXbFVC8qVLvnQMkUpOleAVc5L3CryHcplcqTmY4Pt+Gf tXjGKaI88IH6T+SOZw737PpHr745DcyWzXyYFxhUqfzzIygXPYuztcWMdNooU6ZBsvBQ U5Yg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=sIyfuO6L8HnU8CmCldKrIpDi7aTZJyxJfn1wljTzIeI=; b=ijMKKStsaTT14hNkFE01kEl5JP/h2MWruEIyM6BTf+AxRM+IVyORAZrsPha63LnCIX qiDB88VHs/xP/iUddCEECIHmr1CSvT/HHCd++2T7u/0DqIkixT+H4fCUOEAYddtg2FeK V609AF7q4hb4wSDsyEms1WSkocZ81isCUieE/OWcDCP8WRFyOvyux2zb3knmbHjhMhQ+ Pv7WZtutlRvyt9idQa9Ozejq+fAjCIphFRnpbipOmetoQSB6fBmTDcSIBxT26I90nJKA 8u0Xb4Ocbjf4buQWf3gakdsmcxY1bOqa29606hCZETfGeofo4HhTWelePS58DJxq2Jio c6/A== X-Gm-Message-State: AFqh2kqu03RUUl5/y986hBc84477lok6BB31BTse57cXrxaud8WaKId7 FjMdtLjJUheFka6W7UWM5d/y4CUhvJCXNDXu X-Google-Smtp-Source: AMrXdXvOH+6kWmrNXWr4DzT0DiqLcTz70aEBBsdc901akacOkyNgSBf4mYJaruRIUQ+DNlIh+bmPNeoAoGZ2Pser X-Received: from vannapurve2.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:41f8]) (user=vannapurve job=sendgmr) by 2002:a17:90a:7c48:b0:225:ff38:5494 with SMTP id e8-20020a17090a7c4800b00225ff385494mr796035pjl.151.1672255496443; Wed, 28 Dec 2022 11:24:56 -0800 (PST) Date: Wed, 28 Dec 2022 19:24:38 +0000 In-Reply-To: <20221228192438.2835203-1-vannapurve@google.com> Mime-Version: 1.0 References: <20221228192438.2835203-1-vannapurve@google.com> X-Mailer: git-send-email 2.39.0.314.g84b9a713c41-goog Message-ID: <20221228192438.2835203-5-vannapurve@google.com> Subject: [V4 PATCH 4/4] KVM: selftests: x86: Invoke kvm hypercall as per host cpu From: Vishal Annapurve To: x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: pbonzini@redhat.com, shuah@kernel.org, bgardon@google.com, seanjc@google.com, oupton@google.com, peterx@redhat.com, vkuznets@redhat.com, dmatlack@google.com, Vishal Annapurve Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Invoke vmcall/vmmcall instructions from kvm_hypercall as per host CPU type. CVMs and current kvm_hyerpcall callers need to execute hypercall as per the cpu type to avoid KVM having to emulate the instruction anyways. CVMs need to avoid KVM emulation as the guest code is not updatable from KVM. Guest code region can be marked un-mondifiable from KVM without CVMs as well, so in general it's safer to avoid KVM emulation for vmcall/vmmcall instructions. Suggested-by: Sean Christopherson Signed-off-by: Vishal Annapurve --- tools/testing/selftests/kvm/lib/x86_64/processor.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/tes= ting/selftests/kvm/lib/x86_64/processor.c index 18f0608743d1..cc0b9c17fa91 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -1154,9 +1154,15 @@ uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uin= t64_t a1, uint64_t a2, { uint64_t r; =20 - asm volatile("vmcall" + asm volatile("test %[use_vmmcall], %[use_vmmcall]\n\t" + "jnz 1f\n\t" + "vmcall\n\t" + "jmp 2f\n\t" + "1: vmmcall\n\t" + "2:" : "=3Da"(r) - : "a"(nr), "b"(a0), "c"(a1), "d"(a2), "S"(a3)); + : "a"(nr), "b"(a0), "c"(a1), "d"(a2), "S"(a3), + [use_vmmcall] "r" (is_host_cpu_amd())); return r; } =20 --=20 2.39.0.314.g84b9a713c41-goog