From nobody Sat Feb 7 18:15:52 2026 Received: from out-172.mta0.migadu.com (out-172.mta0.migadu.com [91.218.175.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BC12B482FA for ; Mon, 19 Feb 2024 18:58:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708369107; cv=none; b=ePrMEKKjfefBlXVD12eAYNccFWXNRVUrS/1nqRzszoBCCrE94R85eLZheAIVmx4GpkSgzyQNTMjRTTul15HH2Knq4t7koajSg9UIeGarjRHvp2pUkPtpSa3UP9hodDrnQG6MrqLBwmQo+kmdnuBStd+dIafV/9zk+YqD2fgEzRI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708369107; c=relaxed/simple; bh=yXY4BKwNMqksd8A/oUnvq+Iq0aUB3gr/Y3i4+5lzsvA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XEiV+Dxi6peydmR5eKuE/t/Sko1MTkGYG6mKlzR2Q3XYeY/gDQNDy63yAzdqV5nPLPoMmrFjhHtAOl9AjVvIfoZ7VtJqj4g0ooXSnNgIcOrgg6e+jP+tGm72h2WbIrnJpFJE09JgwkCu/VE11w9Z9bBS0EYNU/d7i/dC2mfkCQ4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=TymjM0U4; arc=none smtp.client-ip=91.218.175.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="TymjM0U4" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1708369103; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=malznfxmTFeYI5AQuBOcx//3J2Klq63IEw4UgO+FW8I=; b=TymjM0U4219Zm3uEd/Lb8NxsD72R3xzRJZRLZBjvd9XHgLBu8YMPWhynBzrl8JRv3paxch lwj9pWCJOssGT/aTbkmYfA4DY/0hoWqJyMUQMa+NXEZkMY7B5s52UXj0Q2QgC1umO8It4y kkbdXBlbN4LMCE9vFrfXl6eQVykFEc8= From: Oliver Upton To: Thomas Gleixner Cc: Marc Zyngier , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, Jing Zhang , Oliver Upton , stable@vger.kernel.org, George Cherian Subject: [PATCH 1/3] irqchip/gic-v3-its: Do not assume vPE tables are preallocated Date: Mon, 19 Feb 2024 18:58:06 +0000 Message-ID: <20240219185809.286724-2-oliver.upton@linux.dev> In-Reply-To: <20240219185809.286724-1-oliver.upton@linux.dev> References: <20240219185809.286724-1-oliver.upton@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" We go through quite a bit of trouble to make sure we pick up any preallocated LPI tables on the redistributors, as enabling LPIs is a one-way switch. There is no such restriction for vLPIs, and for GICv4.1 we expect to allocate a new vPE table at boot. This works as intended when initializing an ITS, however when setting up a redistributor in its_cpu_init_lpis() the early return for preallocated RD tables skips straight past GICv4 setup. This all comes to a head when trying to kexec into a new kernel, as the new kernel silently fails to set up GICv4, leading to a complete loss of SGIs and LPIs for KVM VMs (ouch). Slap a band-aid on the problem by ensuring its_cpu_init_lpis() always initializes GICv4 on the way out, even if the other RD tables were preallocated. Cc: stable@vger.kernel.org Fixes: 6479450f72c1 ("irqchip/gic-v4: Fix occasional VLPI drop") Reported-by: George Cherian Co-developed-by: Marc Zyngier Signed-off-by: Marc Zyngier Signed-off-by: Oliver Upton --- I debated a bit on the fixes tag between the blamed commit and commit 5e5168461c22 ("irqchip/gic-v4.1: VPE table (aka GICR_VPROPBASER) allocation"), although it would appear GICv4 could be left in an unknown state after kexec too. drivers/irqchip/irq-gic-v3-its.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-= its.c index d097001c1e3e..0022852ce494 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -3172,6 +3172,7 @@ static void its_cpu_init_lpis(void) val |=3D GICR_CTLR_ENABLE_LPIS; writel_relaxed(val, rbase + GICR_CTLR); =20 +out: if (gic_rdists->has_vlpis && !gic_rdists->has_rvpeid) { void __iomem *vlpi_base =3D gic_data_rdist_vlpi_base(); =20 @@ -3207,7 +3208,6 @@ static void its_cpu_init_lpis(void) =20 /* Make sure the GIC has seen the above */ dsb(sy); -out: gic_data_rdist()->flags |=3D RD_LOCAL_LPI_ENABLED; pr_info("GICv3: CPU%d: using %s LPI pending table @%pa\n", smp_processor_id(), --=20 2.44.0.rc0.258.g7320e95886-goog From nobody Sat Feb 7 18:15:52 2026 Received: from out-188.mta0.migadu.com (out-188.mta0.migadu.com [91.218.175.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 87D61487B8 for ; Mon, 19 Feb 2024 18:58:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.188 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708369109; cv=none; b=uQfIsX+wZMS8JLUfh/mZifPGgfRoSgoh4ojjv8bl6QLLb/aK7pkWI9r0/e9ZfYZ67CJn9MK0615jM0oQJqlHgH1d5sROMJhONVjn+Opbkbpo8vsNJ+KaEXUfYnjLmvkmMltc/UYpPxtE/B+WywUZ+xBkTdAqQakO7/fgBN+br8E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708369109; c=relaxed/simple; bh=sQ09ukYCJMs0FVbHxpjJQwqr/OlvaGUdTVWxvm0dbCw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pvAM40z7/Jz4RUdwYOYkGdX96x7duDtQvoXcl2h0kFWn7iE8m176SxFaVdl5lQ/Ir4IhVrh2vDz8JRTCtpmvRDj+NaYNujf4Wz2hbHrHbIClQ4G5mrPHpumGGMcAsO47K662CSQjpOvMldqPs82/b7lku8TvrBU7j1R5EUarkf4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=MRaf230x; arc=none smtp.client-ip=91.218.175.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="MRaf230x" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1708369105; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=n0uvz70joVA5h7nCkx+6qjmdsOAE7FpYRNnHlS3lny0=; b=MRaf230xQXz2XUHhNl+qaNg7U148naafFkbpIjvX5ofDIryb/ebMbKl5AfD5yIdB2kC01m TSiy2qQWMMmXuqWaBa+9n70/T2Rb0eTsoKGEIAtME5P0eyHqLqsVN+VLPwaNManRBOUCU+ QyOgXYqz7O7W3v3Lo+/zZnKrDywl9lU= From: Oliver Upton To: Thomas Gleixner Cc: Marc Zyngier , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, Jing Zhang , Oliver Upton Subject: [PATCH 2/3] irqchip/gic-v3-its: Spin off GICv4 init into a separate function Date: Mon, 19 Feb 2024 18:58:07 +0000 Message-ID: <20240219185809.286724-3-oliver.upton@linux.dev> In-Reply-To: <20240219185809.286724-1-oliver.upton@linux.dev> References: <20240219185809.286724-1-oliver.upton@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" Burying the GICv4 redistributor initialization into the routine for LPIs is a bit confusing, and can lead to sillies where unexpected codepaths may not fully initialize the RD. Hoist it out of its_cpu_init_lpis() into a dedicated function. Signed-off-by: Oliver Upton --- drivers/irqchip/irq-gic-v3-its.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-= its.c index 0022852ce494..63d1743f08cc 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -3173,8 +3173,25 @@ static void its_cpu_init_lpis(void) writel_relaxed(val, rbase + GICR_CTLR); =20 out: - if (gic_rdists->has_vlpis && !gic_rdists->has_rvpeid) { + /* Make sure the GIC has seen the above */ + dsb(sy); + gic_data_rdist()->flags |=3D RD_LOCAL_LPI_ENABLED; + pr_info("GICv3: CPU%d: using %s LPI pending table @%pa\n", + smp_processor_id(), + gic_data_rdist()->flags & RD_LOCAL_PENDTABLE_PREALLOCATED ? + "reserved" : "allocated", + &paddr); +} + +static void its_cpu_init_vlpis(void) +{ + /* No vLPIs? No problem. */ + if (!gic_rdists->has_vlpis) + return; + + if (!gic_rdists->has_rvpeid) { void __iomem *vlpi_base =3D gic_data_rdist_vlpi_base(); + u64 val; =20 /* * It's possible for CPU to receive VLPIs before it is @@ -3193,7 +3210,8 @@ static void its_cpu_init_lpis(void) * ancient programming gets left in and has possibility of * corrupting memory. */ - val =3D its_clear_vpend_valid(vlpi_base, 0, 0); + its_clear_vpend_valid(vlpi_base, 0, 0); + return; } =20 if (allocate_vpe_l1_table()) { @@ -3205,15 +3223,6 @@ static void its_cpu_init_lpis(void) gic_rdists->has_rvpeid =3D false; gic_rdists->has_vlpis =3D false; } - - /* Make sure the GIC has seen the above */ - dsb(sy); - gic_data_rdist()->flags |=3D RD_LOCAL_LPI_ENABLED; - pr_info("GICv3: CPU%d: using %s LPI pending table @%pa\n", - smp_processor_id(), - gic_data_rdist()->flags & RD_LOCAL_PENDTABLE_PREALLOCATED ? - "reserved" : "allocated", - &paddr); } =20 static void its_cpu_init_collection(struct its_node *its) @@ -5265,6 +5274,7 @@ int its_cpu_init(void) return ret; =20 its_cpu_init_lpis(); + its_cpu_init_vlpis(); its_cpu_init_collections(); } =20 --=20 2.44.0.rc0.258.g7320e95886-goog From nobody Sat Feb 7 18:15:52 2026 Received: from out-176.mta0.migadu.com (out-176.mta0.migadu.com [91.218.175.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4C878487A3 for ; Mon, 19 Feb 2024 18:58:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.176 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708369111; cv=none; b=HKqRKFi4IOuQVELcYHEoNJpne7FRovAFyhU6SmgYicZ04pFNPRAl4iGBADCweW48c5ZYfcmtGDZMGgU+fUJJBpYh/35TdHHO+BenfFq66v6RLCkpR89Dl7N6vKckt/N6NzI28qELWsBKvMcQLwHB2/g5UU31apiJecUYa8pBbRA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708369111; c=relaxed/simple; bh=AVsdCCM8FvfXsv0NexSqvyqeP7RkJJs+vf3bnHoUDbA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AEQqmj4F2Xja86x2jUzuRUZuLloyU+bBvIKgZUjQUP5MmkqFAtBI6Tnx7gVDP5i1RdnF7Lv8ZqEXV9wL+KUVqve3pDHLAZ4V9IchL+05SGssmolAJVchs0IYuAWTBHDkLZWTCqQf4gyJbns2rvh5Gl6VgLj5PhWKmuAg55cMnPc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=erdwcROx; arc=none smtp.client-ip=91.218.175.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="erdwcROx" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1708369107; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=O6mYbl34iGDajSSuwNwYK5N248BsKIXOEJAXAf9uLUE=; b=erdwcROxjTVj9GYsF9NxwZtHNpUShYCx45EDDOMeS+jAJihxWdrPa0U1lhk/4/FnuC7+2g 6JUYy8lf8giYc6dFvutLvzVCiE2tKOwcceN27OylehFuPrm9rlUze2Uoy930paO+8vWiFX OVADPtybepCZRTctZIlkmbbnW0WSTKY= From: Oliver Upton To: Thomas Gleixner Cc: Marc Zyngier , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, Jing Zhang , Oliver Upton Subject: [PATCH 3/3] irqchip/gic-v3-its: Print the vPE table installed in redistributor Date: Mon, 19 Feb 2024 18:58:08 +0000 Message-ID: <20240219185809.286724-4-oliver.upton@linux.dev> In-Reply-To: <20240219185809.286724-1-oliver.upton@linux.dev> References: <20240219185809.286724-1-oliver.upton@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" Hindsight is 20/20 of course, but the recent vPE table programming bug could've been root caused a bit more quickly if we print the table getting installed at every redistributor. Promote to pr_info() and add some additional context, such as the provenance of the installed vPE table. Signed-off-by: Oliver Upton --- drivers/irqchip/irq-gic-v3-its.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-= its.c index 63d1743f08cc..c3ef9665a2ad 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -2835,7 +2835,8 @@ static int allocate_vpe_l1_table(void) u64 val, gpsz, npg, pa; unsigned int psz =3D SZ_64K; unsigned int np, epp, esz; - struct page *page; + struct page *page =3D NULL; + bool from_its =3D false; =20 if (!gic_rdists->has_rvpeid) return 0; @@ -2865,8 +2866,10 @@ static int allocate_vpe_l1_table(void) return -ENOMEM; =20 val =3D inherit_vpe_l1_table_from_its(); - if (val & GICR_VPROPBASER_4_1_VALID) + if (val & GICR_VPROPBASER_4_1_VALID) { + from_its =3D true; goto out; + } =20 /* First probe the page size */ val =3D FIELD_PREP(GICR_VPROPBASER_4_1_PAGE_SIZE, GIC_PAGE_SIZE_64K); @@ -2945,9 +2948,12 @@ static int allocate_vpe_l1_table(void) gicr_write_vpropbaser(val, vlpi_base + GICR_VPROPBASER); cpumask_set_cpu(smp_processor_id(), gic_data_rdist()->vpe_table_mask); =20 - pr_debug("CPU%d: VPROPBASER =3D %llx %*pbl\n", - smp_processor_id(), val, - cpumask_pr_args(gic_data_rdist()->vpe_table_mask)); + pr_info("CPU%d: Using %s vPE table @%llx (%s)\n", + smp_processor_id(), + (val & GICR_VPROPBASER_4_1_INDIRECT) ? "indirect" : "direct", + val & GICR_VPROPBASER_4_1_ADDR, + (page) ? "allocated" : + ((from_its) ? "inherited from ITS" : "inherited from RD")); =20 return 0; } --=20 2.44.0.rc0.258.g7320e95886-goog