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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C7C0CC433EF for ; Tue, 28 Dec 2021 10:30:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Subject:Cc:To:From:Message-ID:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ReahcnFAVcLG92HGSWlNVk1hYImCMl7p7VL7+LxUGjM=; b=LzzJ6L3XGQ+5w2 mcTLov66n4uM1qjIxkZ6X/BDFvtdUmaP0xVuBE2Lnv9weWKz5rts8vc+5+kGW9cDnadm5XsUOAlyQ I+NqI5AIYT3KTX/OMBszOtO52TKiRU+WSZRX9L26220SxJpzCSAyWD2jI2CPaRpovaIy2s0F9SATD K+VVuA6mI2ow+9jUmCpYfzncbyj4+Rv/2VNUqPWblyYd7tVziPdkwzoOZcSAM315H52a2QQMVUQot fjfIidde9pedhiBawhqPRbDWe25OCOISv6W6IzywOLnYJBPV3eO7eR8SnuEF8yK0Ybd6csZif+AOB Jk1t5vq6TzgSzYC1YTrw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n29jT-000gkg-AX; Tue, 28 Dec 2021 10:29:27 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1n29jP-000gjY-JB for linux-arm-kernel@lists.infradead.org; Tue, 28 Dec 2021 10:29:25 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EAC9E6119F; Tue, 28 Dec 2021 10:29:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5F7D8C36AE7; Tue, 28 Dec 2021 10:29:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1640687362; bh=jUyAI10oL4qbXf6iPtMaNEXBvDx/0AR7LVT2O/v4TWI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=cYpICZh/loys4dXwcO2vbPA9qMpPzWNJWm+fUksX2gTD0aPkW3R9ZUs1TUJQHWEON FxecWJbmzXOu99MGmOdkEa/gGaryaiohlHN1t8Y9lYe2OYPyafshclZtVrQ5Ix3cb7 3Y+017I58oCK3x23nAD6aF2/8IL0qyGSGf0T+c48BNLFphIo9/6lifcVMQWGWkscq5 KVJ0de3MbETLH0yo6OESTwlT1m6cgQouNKGV6VN4tZiTChb75EMP9DN/m6u/CsHYji ycgwLg/3V5MVwcXtDmlNkMguR0JbDNkUn1EN/UftP3vMFuj+O4r2e3onK+E8ONctas rolHvY0oCtP0g== Received: from cfbb000407.r.cam.camfibre.uk ([185.219.108.64] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1n29jL-00Ehcz-VK; Tue, 28 Dec 2021 10:29:20 +0000 Date: Tue, 28 Dec 2021 10:29:35 +0000 Message-ID: <87lf05yqcw.wl-maz@kernel.org> From: Marc Zyngier To: Andrew Jones Cc: Paolo Bonzini , James Morse , Suzuki K Poulose , Alexandru Elisei , kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kernel-team@android.com Subject: Re: [PATCH v2 2/6] KVM: selftests: arm64: Introduce a variable default IPA size In-Reply-To: <20211228092622.ffw7xu2j5ow4njxo@gator.home> References: <20211227124809.1335409-1-maz@kernel.org> <20211227124809.1335409-3-maz@kernel.org> <20211228092622.ffw7xu2j5ow4njxo@gator.home> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: drjones@redhat.com, pbonzini@redhat.com, james.morse@arm.com, suzuki.poulose@arm.com, alexandru.elisei@arm.com, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211228_022923_747500_207909D7 X-CRM114-Status: GOOD ( 34.55 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 28 Dec 2021 09:26:22 +0000, Andrew Jones wrote: > > On Mon, Dec 27, 2021 at 12:48:05PM +0000, Marc Zyngier wrote: > > Contrary to popular belief, there is no such thing as a default > > IPA size on arm64. Anything goes, and implementations are the > > usual Wild West. > > > > The selftest infrastructure default to 40bit IPA, which obviously > > doesn't work for some systems out there. > > > > Turn VM_MODE_DEFAULT from a constant into a variable, and let > > guest_modes_append_default() populate it, depending on what > > the HW can do. In order to preserve the current behaviour, we > > still pick 40bits IPA as the default if it is available, and > > the largest supported IPA space otherwise. > > > > Signed-off-by: Marc Zyngier > > --- > > .../testing/selftests/kvm/include/kvm_util.h | 4 ++- > > tools/testing/selftests/kvm/lib/guest_modes.c | 30 +++++++++++++++++-- > > 2 files changed, 30 insertions(+), 4 deletions(-) > > > > diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h > > index 2d62edc49d67..7fa0a93d7526 100644 > > --- a/tools/testing/selftests/kvm/include/kvm_util.h > > +++ b/tools/testing/selftests/kvm/include/kvm_util.h > > @@ -53,7 +53,9 @@ enum vm_guest_mode { > > > > #if defined(__aarch64__) > > > > -#define VM_MODE_DEFAULT VM_MODE_P40V48_4K > > +extern enum vm_guest_mode vm_mode_default; > > + > > +#define VM_MODE_DEFAULT vm_mode_default > > #define MIN_PAGE_SHIFT 12U > > #define ptes_per_page(page_size) ((page_size) / 8) > > > > diff --git a/tools/testing/selftests/kvm/lib/guest_modes.c b/tools/testing/selftests/kvm/lib/guest_modes.c > > index c330f414ef96..5e3fdbd992fd 100644 > > --- a/tools/testing/selftests/kvm/lib/guest_modes.c > > +++ b/tools/testing/selftests/kvm/lib/guest_modes.c > > @@ -4,22 +4,46 @@ > > */ > > #include "guest_modes.h" > > > > +#ifdef __aarch64__ > > +enum vm_guest_mode vm_mode_default; > > +#endif > > + > > struct guest_mode guest_modes[NUM_VM_MODES]; > > > > void guest_modes_append_default(void) > > { > > +#ifndef __aarch64__ > > guest_mode_append(VM_MODE_DEFAULT, true, true); > > - > > -#ifdef __aarch64__ > > - guest_mode_append(VM_MODE_P40V48_64K, true, true); > > +#else > > { > > unsigned int limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE); > > + int i; > > + > > + vm_mode_default = NUM_VM_MODES; > > + > > if (limit >= 52) > > guest_mode_append(VM_MODE_P52V48_64K, true, true); > > if (limit >= 48) { > > guest_mode_append(VM_MODE_P48V48_4K, true, true); > > guest_mode_append(VM_MODE_P48V48_64K, true, true); > > } > > + if (limit >= 40) { > > + guest_mode_append(VM_MODE_P40V48_4K, true, true); > > + guest_mode_append(VM_MODE_P40V48_64K, true, true); > > + vm_mode_default = VM_MODE_P40V48_4K; > > + } > > + > > + /* > > + * Pick the first supported IPA size if the default > > + * isn't available. > > + */ > > + for (i = 0; vm_mode_default == NUM_VM_MODES && i < NUM_VM_MODES; i++) { > > + if (guest_modes[i].supported && guest_modes[i].enabled) > > + vm_mode_default = i; > > Since we don't have a 'break' here, this picks the last supported size > (of the guest_modes list), not the first, as the comment implies it should > do. This is checked in the for() loop condition, and the first matching mode will cause the loop to terminate. This is the same check that avoids scanning for a mode when VM_MODE_P40V48_4K is selected. M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel