From patchwork Wed Apr 12 18:50:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Woodhouse X-Patchwork-Id: 1768232 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; secure) header.d=infradead.org header.i=@infradead.org header.a=rsa-sha256 header.s=casper.20170209 header.b=XNrj8BMA; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4PxWzl4H2Bz1ybJ for ; Thu, 13 Apr 2023 04:52:35 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pmfYt-0000kI-ER; Wed, 12 Apr 2023 14:51:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pmfYm-0000iw-Lc for qemu-devel@nongnu.org; Wed, 12 Apr 2023 14:51:13 -0400 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pmfYk-0003BH-AN for qemu-devel@nongnu.org; Wed, 12 Apr 2023 14:51:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=tO8ebQO7hdBkDVSP4r+H8wDgeYM8ejzEVuKZ0cLSybE=; b=XNrj8BMABVv6sUMXdtjglSDnX8 3vqc0BHSKUVoTm4KdYsPLXfvX4sg8NBLll2N3jWqzzy1XjtXhTso4UClv3zK+Wo/lXaWTIKROWAXk n8V6T9UBtmYBSg9NMdsP7hiQhPxZoolCMSUzWdMFVrb/wHfVc4To4//Se0e86u8oU9+t4hyPezTbH f5MJasfK2wQfTiJs7w5l/hYZYx2CDcsMh7Hwr5uho1w8CUdyi62f2QwEgOT7RJLjBRi8CwnVD9JNN 4T2rynFSIcpVIvoF02xBSckWGDbUY0yH2mpFcVj7EgK7zOJFQpvAXN7f/sN77jA/1LGpvocufAjv5 3J7SUvwQ==; Received: from [2001:8b0:10b:5::ebe] (helo=i7.infradead.org) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1pmfYf-0077lC-4l; Wed, 12 Apr 2023 18:51:05 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1pmfYe-001r1E-1o; Wed, 12 Apr 2023 19:51:04 +0100 From: David Woodhouse To: qemu-devel@nongnu.org Cc: no Stabellini , Anthony Perard , Paul Durrant , =?utf-8?q?Marc-Andr=C3=A9_Lureau?= , Paolo Bonzini , Richard Henderson , Eduardo Habkost , "Michael S. Tsirkin" , Marcel Apfelbaum , =?utf-8?q?Daniel_P=2E_Berran?= =?utf-8?q?g=C3=A9?= , Thomas Huth , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , xen-devel@lists.xenproject.org Subject: [PATCH 1/5] hw/xen: Simplify emulated Xen platform init Date: Wed, 12 Apr 2023 19:50:58 +0100 Message-Id: <20230412185102.441523-2-dwmw2@infradead.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230412185102.441523-1-dwmw2@infradead.org> References: <20230412185102.441523-1-dwmw2@infradead.org> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Received-SPF: none client-ip=2001:8b0:10b:1236::1; envelope-from=BATV+9719990f4703cc1bc73b+7171+infradead.org+dwmw2@casper.srs.infradead.org; helo=casper.infradead.org X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: David Woodhouse I initially put the basic platform init (overlay pages, grant tables, event channels) into mc->kvm_type because that was the earliest place that could sensibly test for xen_mode==XEN_EMULATE. The intent was to do this early enough that we could then initialise the XenBus and other parts which would have depended on them, from a generic location for both Xen and KVM/Xen in the PC-specific code, as seen in https://lore.kernel.org/qemu-devel/20230116221919.1124201-16-dwmw2@infradead.org/ However, then the Xen on Arm patches came along, and *they* wanted to do the XenBus init from a 'generic' Xen-specific location instead: https://lore.kernel.org/qemu-devel/20230210222729.957168-4-sstabellini@kernel.org/ Since there's no generic location that covers all three, I conceded to do it for XEN_EMULATE mode in pc_basic_devices_init(). And now there's absolutely no point in having some of the platform init done from pc_machine_kvm_type(); we can move it all up to live in a single place in pc_basic_devices_init(). This has the added benefit that we can drop the separate xen_evtchn_connect_gsis() function completely, and pass just the system GSIs in directly to xen_evtchn_create(). While I'm at it, it does no harm to explicitly pass in the *number* of said GSIs, because it does make me twitch a bit to pass an array of impicit size. During the lifetime of the KVM/Xen patchset, that had already changed (albeit just cosmetically) from GSI_NUM_PINS to IOAPIC_NUM_PINS. And document a bit better that this is for the *output* GSI for raising CPU0's events when the per-CPU vector isn't available. The fact that we create a whole set of them and then only waggle the one we're told to, instead of having a single output and only *connecting* it to the GSI that it should be connected to, is still non-intuitive for me. Signed-off-by: David Woodhouse Reviewed-by: Paul Durrant --- hw/i386/kvm/xen_evtchn.c | 40 ++++++++++++++++++++-------------------- hw/i386/kvm/xen_evtchn.h | 3 +-- hw/i386/pc.c | 13 ++++--------- 3 files changed, 25 insertions(+), 31 deletions(-) diff --git a/hw/i386/kvm/xen_evtchn.c b/hw/i386/kvm/xen_evtchn.c index 3048329474..3d810dbd59 100644 --- a/hw/i386/kvm/xen_evtchn.c +++ b/hw/i386/kvm/xen_evtchn.c @@ -147,7 +147,10 @@ struct XenEvtchnState { QemuMutex port_lock; uint32_t nr_ports; XenEvtchnPort port_table[EVTCHN_2L_NR_CHANNELS]; - qemu_irq gsis[IOAPIC_NUM_PINS]; + + /* Connected to the system GSIs for raising callback as GSI / INTx */ + unsigned int nr_callback_gsis; + qemu_irq *callback_gsis; struct xenevtchn_handle *be_handles[EVTCHN_2L_NR_CHANNELS]; @@ -299,7 +302,7 @@ static void gsi_assert_bh(void *opaque) } } -void xen_evtchn_create(void) +void xen_evtchn_create(unsigned int nr_gsis, qemu_irq *system_gsis) { XenEvtchnState *s = XEN_EVTCHN(sysbus_create_simple(TYPE_XEN_EVTCHN, -1, NULL)); @@ -310,8 +313,19 @@ void xen_evtchn_create(void) qemu_mutex_init(&s->port_lock); s->gsi_bh = aio_bh_new(qemu_get_aio_context(), gsi_assert_bh, s); - for (i = 0; i < IOAPIC_NUM_PINS; i++) { - sysbus_init_irq(SYS_BUS_DEVICE(s), &s->gsis[i]); + /* + * These are the *output* GSI from event channel support, for + * signalling CPU0's events via GSI or PCI INTx instead of the + * per-CPU vector. We create a *set* of irqs and connect one to + * each of the system GSIs which were passed in from the platform + * code, and then just trigger the right one as appropriate from + * xen_evtchn_set_callback_level(). + */ + s->nr_callback_gsis = nr_gsis; + s->callback_gsis = g_new0(qemu_irq, nr_gsis); + for (i = 0; i < nr_gsis; i++) { + sysbus_init_irq(SYS_BUS_DEVICE(s), &s->callback_gsis[i]); + sysbus_connect_irq(SYS_BUS_DEVICE(s), i, system_gsis[i]); } /* @@ -336,20 +350,6 @@ void xen_evtchn_create(void) xen_evtchn_ops = &emu_evtchn_backend_ops; } -void xen_evtchn_connect_gsis(qemu_irq *system_gsis) -{ - XenEvtchnState *s = xen_evtchn_singleton; - int i; - - if (!s) { - return; - } - - for (i = 0; i < IOAPIC_NUM_PINS; i++) { - sysbus_connect_irq(SYS_BUS_DEVICE(s), i, system_gsis[i]); - } -} - static void xen_evtchn_register_types(void) { type_register_static(&xen_evtchn_info); @@ -430,8 +430,8 @@ void xen_evtchn_set_callback_level(int level) return; } - if (s->callback_gsi && s->callback_gsi < IOAPIC_NUM_PINS) { - qemu_set_irq(s->gsis[s->callback_gsi], level); + if (s->callback_gsi && s->callback_gsi < s->nr_callback_gsis) { + qemu_set_irq(s->callback_gsis[s->callback_gsi], level); if (level) { /* Ensure the vCPU polls for deassertion */ kvm_xen_set_callback_asserted(); diff --git a/hw/i386/kvm/xen_evtchn.h b/hw/i386/kvm/xen_evtchn.h index bfb67ac2bc..b740acfc0d 100644 --- a/hw/i386/kvm/xen_evtchn.h +++ b/hw/i386/kvm/xen_evtchn.h @@ -16,10 +16,9 @@ typedef uint32_t evtchn_port_t; -void xen_evtchn_create(void); +void xen_evtchn_create(unsigned int nr_gsis, qemu_irq *system_gsis); int xen_evtchn_soft_reset(void); int xen_evtchn_set_callback_param(uint64_t param); -void xen_evtchn_connect_gsis(qemu_irq *system_gsis); void xen_evtchn_set_callback_level(int level); int xen_evtchn_set_port(uint16_t port); diff --git a/hw/i386/pc.c b/hw/i386/pc.c index 1489abf010..25584cb8f3 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1319,7 +1319,10 @@ void pc_basic_device_init(struct PCMachineState *pcms, #ifdef CONFIG_XEN_EMU if (xen_mode == XEN_EMULATE) { - xen_evtchn_connect_gsis(gsi); + xen_overlay_create(); + xen_evtchn_create(IOAPIC_NUM_PINS, gsi); + xen_gnttab_create(); + xen_xenstore_create(); if (pcms->bus) { pci_create_simple(pcms->bus, -1, "xen-platform"); } @@ -1868,14 +1871,6 @@ static void pc_machine_initfn(Object *obj) int pc_machine_kvm_type(MachineState *machine, const char *kvm_type) { -#ifdef CONFIG_XEN_EMU - if (xen_mode == XEN_EMULATE) { - xen_overlay_create(); - xen_evtchn_create(); - xen_gnttab_create(); - xen_xenstore_create(); - } -#endif return 0; }