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smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tcZZUlY4; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="tcZZUlY4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F937C4CEED; Tue, 3 Jun 2025 14:24:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748960685; bh=8P8VpDyERLX0d7YNci0mUwMHPwaKMA33bffoWYiDOoQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tcZZUlY4T6EfydwCQ090MG6vqI7M4UU9SIKhGZRzBEnWbgz/cP1Uy/djS+adVoJNQ NwWME4e3vLT/EELNQnDkSgIN0y1aNf4ZGKWCDPo5D/xAPt+q4hyNS6UnuXOlGufVCl aSfrdoWeAuHab//2ghDX/LhcrAp3UOwKdAf3lstikV4Pwg0tWWdtTEHK0Wlkc2A2J9 0E8lWXJQ7ZH959nry1KBohTeWMB1TgLyBaAE0YS174Cyqn+Qc2mHz4wROWHJwkjj/F IroNYxEkovS4Ok4uCF7bLQH9LS2TKBRRB9hAYYB6BvLia1enGpH7axLzxTsG99QxfF VSXmpo7Rrykwg== Date: Tue, 3 Jun 2025 16:24:40 +0200 From: Lorenzo Pieralisi To: Marc Zyngier Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Thomas Gleixner , Zenghui Yu Subject: Re: [PATCH] PCI/MSI: Size device MSI domain with the maximum number of vectors Message-ID: References: <20250603141801.915305-1-maz@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250603141801.915305-1-maz@kernel.org> On Tue, Jun 03, 2025 at 03:18:01PM +0100, Marc Zyngier wrote: > Zenghui reports that since 1396e89e09f0 ("genirq/msi: Move prepare() > call to per-device allocation"), his Multi-MSI capable device isn't > working anymore. > > This is a consequence of 15c72f824b32 ("PCI/MSI: Add support for > per device MSI[X] domains"), which always creates a MSI domain of > size 1, even in the presence of Multi-MSI. > > While this was somehow working until then, moving the .prepare() > call ends up sizing the ITS table with a tiny value for this device, > and making the endpoint driver unhappy. > > Instead, always create the domain (and call the .prepare() helper) > with the maximum expected size. > > Fixes: 1396e89e09f0 ("genirq/msi: Move prepare() call to per-device allocation") > Fixes: 15c72f824b32 ("PCI/MSI: Add support for per device MSI[X] domains") > Link: https://lore.kernel.org/r/0b1d7aec-1eac-a9cd-502a-339e216e08a1@huawei.com > Reported-by: Zenghui Yu > Tested-by: Zenghui Yu > Signed-off-by: Marc Zyngier > --- > drivers/pci/msi/irqdomain.c | 5 +++-- > drivers/pci/msi/msi.c | 8 ++++---- > drivers/pci/msi/msi.h | 2 +- > 3 files changed, 8 insertions(+), 7 deletions(-) Reviewed-by: Lorenzo Pieralisi > diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c > index d7ba8795d60f..c05152733993 100644 > --- a/drivers/pci/msi/irqdomain.c > +++ b/drivers/pci/msi/irqdomain.c > @@ -271,6 +271,7 @@ static bool pci_create_device_domain(struct pci_dev *pdev, const struct msi_doma > /** > * pci_setup_msi_device_domain - Setup a device MSI interrupt domain > * @pdev: The PCI device to create the domain on > + * @hwsize: The maximum number of MSI vectors > * > * Return: > * True when: > @@ -287,7 +288,7 @@ static bool pci_create_device_domain(struct pci_dev *pdev, const struct msi_doma > * - The device is removed > * - MSI is disabled and a MSI-X domain is created > */ > -bool pci_setup_msi_device_domain(struct pci_dev *pdev) > +bool pci_setup_msi_device_domain(struct pci_dev *pdev, unsigned int hwsize) > { > if (WARN_ON_ONCE(pdev->msix_enabled)) > return false; > @@ -297,7 +298,7 @@ bool pci_setup_msi_device_domain(struct pci_dev *pdev) > if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSIX)) > msi_remove_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN); > > - return pci_create_device_domain(pdev, &pci_msi_template, 1); > + return pci_create_device_domain(pdev, &pci_msi_template, hwsize); > } > > /** > diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c > index d6ce04054702..6ede55a7c5e6 100644 > --- a/drivers/pci/msi/msi.c > +++ b/drivers/pci/msi/msi.c > @@ -439,16 +439,16 @@ int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec, > if (nvec < minvec) > return -ENOSPC; > > - if (nvec > maxvec) > - nvec = maxvec; > - > rc = pci_setup_msi_context(dev); > if (rc) > return rc; > > - if (!pci_setup_msi_device_domain(dev)) > + if (!pci_setup_msi_device_domain(dev, nvec)) > return -ENODEV; > > + if (nvec > maxvec) > + nvec = maxvec; > + > for (;;) { > if (affd) { > nvec = irq_calc_affinity_vectors(minvec, nvec, affd); > diff --git a/drivers/pci/msi/msi.h b/drivers/pci/msi/msi.h > index fc70b601e942..0b420b319f50 100644 > --- a/drivers/pci/msi/msi.h > +++ b/drivers/pci/msi/msi.h > @@ -107,7 +107,7 @@ enum support_mode { > }; > > bool pci_msi_domain_supports(struct pci_dev *dev, unsigned int feature_mask, enum support_mode mode); > -bool pci_setup_msi_device_domain(struct pci_dev *pdev); > +bool pci_setup_msi_device_domain(struct pci_dev *pdev, unsigned int hwsize); > bool pci_setup_msix_device_domain(struct pci_dev *pdev, unsigned int hwsize); > > /* Legacy (!IRQDOMAIN) fallbacks */ > -- > 2.47.2 >