From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f199.google.com (mail-pg1-f199.google.com [209.85.215.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 073CF4908DE for ; Tue, 28 Jul 2026 22:10:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785276637; cv=none; b=cc5CEFn4cJlCaWZaI7tOkA2vD/1YZ1mCM7G5x/hWMg96KsgN72YsLLhmw/kTMIRkm+4W9zlMe52cl66e31UZ+EggutuPGne9MgnZCKXGp7Fy+wS2DNGb7ottukwgTekx56kXu761wGChDB+uZI7Mqpx/lIH8oU4jkhgDCmUm0sU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785276637; c=relaxed/simple; bh=csbyjjA2KjKhgr5ujOtbJqKY6LzOTF83Qklit7gcOmg=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=IhleDf7XFhSNuT+tAITR3OAWRzxm/WHN/j/UoJ3FI+AijUtVh0N94hgtA+C3fDfiXG5+WRkr5KwrBhLrIleBJLB1Tt0sMx4wNYoO/7/9vR/73QnK2AE7c1M+gwN0d/ZXv5C0WHro55D58moHl7WJSRzV0DHeG31W3Bmjbp0tKxU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--dmatlack.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=rLY3UFdZ; arc=none smtp.client-ip=209.85.215.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--dmatlack.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="rLY3UFdZ" Received: by mail-pg1-f199.google.com with SMTP id 41be03b00d2f7-ca7c1e22995so361411a12.3 for ; Tue, 28 Jul 2026 15:10:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1785276629; x=1785881429; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=wIyl1z6VbEjbpTwDm7dyBOXwnjYP7h00s7jMGOKLSmY=; b=rLY3UFdZrM9yMKEzkWIfWyaTAaCxnh6JNyeYQzolF3ZKIh1XZfvdJ80Mvsefn4Ps/a YLTcqzmIzENAzRtMyTob8QlepxxWdbU03vZgxZnPo4NztgL7l4SAWqs/AxZ85hGwOoUP wW7IoojgBpX/RF7PpXigIOmTU5tml1bUuBGdI32ZmvKjngnVOuNOHAxL8Hhc6T3eU4Av VJw09N2bTym0Q5FT3p9FkUNTvC+QnTsoipz6M/5ReOeQPdHr9sxDRn0DYJsrFA/R8tKd lqN9IrvOFJFPVHrx6wMGy8fFtVKdZpohD3Qr9ZKnqRXEqqYB7y7Tf3Kp4vmQa0D/A8iJ Ia1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785276629; x=1785881429; h=content-type: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:content-type; bh=wIyl1z6VbEjbpTwDm7dyBOXwnjYP7h00s7jMGOKLSmY=; b=n/PrPpN5iLqoc9sT3n1f3YpyiBva61DAPRfvmgT6FSlWlCYdepkVRrFV8OtFpRnL2X V2aSRz0xY/hyJqBYZ3uzKll3+bWPLBPZklIZFo8uxKhUMo2x3MmR7qa9Mg6U1R5ED24K KroAdgO5I5jRNiBn+pciNzQbk/mlK3muadrXR53R+xKcG3eDNjOek+keKCnlAzaOWCPl TOv8kl5yhi+W/nHgZE0YqI/mzpVBXf5HhHFfqs+VLgAbrhxFOMSXK74NQlT38mkjBIrz R5Gpz0DARnztlbpEZ+VmvOErAk9+ExMHCARZBj5oYHc37YJo3l2uCevBlkTIXDmq+4Kc j7Vw== X-Forwarded-Encrypted: i=1; AHgh+Rr+kD/GEVJvcBCYa8Fm2yM3EjczJAtB1/S60tIOH2X+X9PUlnW2N3i0d50RaC/GHrb9gdf+oDId11g3Lqk=@vger.kernel.org X-Gm-Message-State: AOJu0YxuNpxVMKjSwcJuBob7mdb1PLzR9P0sb54imlshmbGjf/rGDzjx 4a2IA5qCv8ptALiNwNKpBuChgwLTGDy7UiC+rl5P3Uo4oOZv8Puva6vmEP73OOjSx0NSSIBXLVA Z6aULjxG+/CUgvA== X-Received: from pgbcp14.prod.google.com ([2002:a05:6a02:400e:b0:c96:c217:cd27]) (user=dmatlack job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:3993:b0:3c0:9c19:65a8 with SMTP id adf61e73a8af0-3c8ba62a17dmr5198004637.64.1785276628580; Tue, 28 Jul 2026 15:10:28 -0700 (PDT) Date: Tue, 28 Jul 2026 22:10:03 +0000 In-Reply-To: <20260728221007.2098560-1-dmatlack@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260728221007.2098560-1-dmatlack@google.com> X-Mailer: git-send-email 2.55.0.487.gaf234c4eb3-goog Message-ID: <20260728221007.2098560-10-dmatlack@google.com> Subject: [PATCH v8 09/12] PCI: liveupdate: Adopt ARI Forwarding Enable on preserved bridges From: David Matlack To: kexec@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-pci@vger.kernel.org Cc: Adithya Jayachandran , Alexander Graf , Alex Williamson , Bjorn Helgaas , Chris Li , David Matlack , David Rientjes , Jacob Pan , Jason Gunthorpe , Jonathan Corbet , Josh Hilke , Leon Romanovsky , Lukas Wunner , Mike Rapoport , Parav Pandit , Pasha Tatashin , Pranjal Shrivastava , Pratyush Yadav , Saeed Mahameed , Samiullah Khawaja , Shuah Khan , Vipin Sharma , William Tu , Yi Liu Content-Type: text/plain; charset="UTF-8" Adopt the ARI Forwarding Enable bit on preserved bridges and update pci_dev->ari_enabled accordingly during a Live Update. This ensures that the preserved devices on the bridge's secondary bus can be identified with the same expanded 8-bit function number after a Live Update. Signed-off-by: David Matlack --- drivers/pci/liveupdate.c | 30 ++++++++++++++++++++++++++++++ drivers/pci/liveupdate.h | 6 ++++++ drivers/pci/pci.c | 8 +++++++- 3 files changed, 43 insertions(+), 1 deletion(-) diff --git a/drivers/pci/liveupdate.c b/drivers/pci/liveupdate.c index fb602dd3933e..744513ee11ed 100644 --- a/drivers/pci/liveupdate.c +++ b/drivers/pci/liveupdate.c @@ -128,6 +128,10 @@ * way after Live Update and ensures that IOMMU groups do not change. Note * that a device will use its adopted ACS controls for the lifetime of its * struct pci_dev (i.e. even after pci_liveupdate_finish()). + * + * * The PCI core adopts ARI Forwarding Enable on all bridges with downstream + * preserved devices to ensure that all preserved devices on the bridge's + * secondary bus are addressable after the Live Update. */ #define pr_fmt(fmt) "PCI: liveupdate: " fmt @@ -833,6 +837,32 @@ int pci_liveupdate_enable_adopted_acs_controls(struct pci_dev *dev) return 0; } +/** + * pci_liveupdate_adopt_ari() - Adopt ARI configuration + * @dev: The PCI device to adopt ARI configuration for + * + * For devices preserved across a Live Update, read the ARI state from + * hardware and adopt it. This ensures the device continues to use the ARI + * configuration established by the previous kernel. + * + * Return: 0 on success, or -EINVAL if the device was not preserved. + */ +int pci_liveupdate_adopt_ari(struct pci_dev *dev) +{ + u16 val; + + guard(rwsem_read)(&pci_liveupdate.rwsem); + + if (!dev->liveupdate.incoming) + return -EINVAL; + + pcie_capability_read_word(dev, PCI_EXP_DEVCTL2, &val); + + /* Safe to modify dev->ari_enabled bitfield during enumeration. */ + dev->ari_enabled = !!(val & PCI_EXP_DEVCTL2_ARI); + return 0; +} + /** * pci_liveupdate_is_incoming() - Check if a device is incoming-preserved * @dev: The PCI device to check diff --git a/drivers/pci/liveupdate.h b/drivers/pci/liveupdate.h index ac5b8bf2edf5..ccc23031e99d 100644 --- a/drivers/pci/liveupdate.h +++ b/drivers/pci/liveupdate.h @@ -18,6 +18,7 @@ bool pci_liveupdate_preserve_bus_numbers(struct pci_bus *bus, void pci_liveupdate_scan_bridge_end(struct pci_dev *dev); void pci_liveupdate_cache_adopted_acs_controls(struct pci_dev *dev); int pci_liveupdate_enable_adopted_acs_controls(struct pci_dev *dev); +int pci_liveupdate_adopt_ari(struct pci_dev *dev); #else static inline void pci_liveupdate_setup_device(struct pci_dev *dev) { @@ -45,6 +46,11 @@ static inline int pci_liveupdate_enable_adopted_acs_controls(struct pci_dev *dev { return -EINVAL; } + +static inline int pci_liveupdate_adopt_ari(struct pci_dev *dev) +{ + return -EINVAL; +} #endif #endif /* DRIVERS_PCI_LIVEUPDATE_H */ diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 22001bdf4c97..6922f361a89e 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3528,7 +3528,7 @@ void pci_configure_ari(struct pci_dev *dev) u32 cap; struct pci_dev *bridge; - if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn) + if (!pci_is_pcie(dev) || dev->devfn) return; bridge = dev->bus->self; @@ -3539,6 +3539,12 @@ void pci_configure_ari(struct pci_dev *dev) if (!(cap & PCI_EXP_DEVCAP2_ARI)) return; + if (!pci_liveupdate_adopt_ari(bridge)) + return; + + if (pcie_ari_disabled) + return; + if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI)) { pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_ARI); -- 2.55.0.487.gaf234c4eb3-goog