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[176.36.245.220]) by smtp.gmail.com with ESMTPSA id bt10sm235165lfb.193.2021.11.25.03.03.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 25 Nov 2021 03:03:07 -0800 (PST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 4618b0c5-4ddf-11ec-9787-a32c541c8605 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=v3OzM+kUo0HWtvX10bY+8EGI7EL/11lwc+lbMCf7qNk=; b=jUEMnIzqEnMb2tTxWY2ERzXP+gz/bY9eHslY4VclicZg2ER7+KwvDffPj9x2ZLn7sw ffHw1O40qtnwyNXxYJmMRn4tIPHZomVIPBa55zou05gEwjanHcE3Gh+C9cCEQ0htPb6R PNre5uj/tKGcREoM+UiPIBf0MvRJIYNqly5uJlhBcN6jORMDBbI8cTGxuBcXCsOSUQR9 8hPIWOS7r5EuaK7MlJNL8PzuHvFBrSNMn28dzcmJUjj3nO9NJ08hvNDG4MDuyap8Mz9E xbWnpqnOOnONLnR79ZiQipALs1THJokDQ4StQg6ngoIaCuja8Rp7RK44GO3GGDvj7P3J l+GA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=v3OzM+kUo0HWtvX10bY+8EGI7EL/11lwc+lbMCf7qNk=; b=qKOQqwAWx+FYaS3fdhfAMxY0zIwS9zniOi2EocZ1Z2bazz4Zvzz7iNM8egVuMuubnJ OEbL6uCQAmO88KzJ0Vq0qgQZVgGgKWIsMhSBh1EgzcwjJN9nIoIMy1RO3kZHTX6kG4zo ipXEXSgukVmsxeOut6jF5QTysnpf+2EOw0B0HWuF/JFOX7KtNkNiM1ccQxMhNWYqnHO9 mZbQT+9TNnZ1C3Su9VJYF4spJFA9Dn13onJmn1Cu2bmZ4OgdzMGE9OfU2Io1FOVbACc+ wTAI8WZ4QO7tw4hx9nmnH8XrSM0yu6KI+BO6nYjFK4PzPuPaDtX1xEqWV3cXydptK1Sh WS2g== X-Gm-Message-State: AOAM532X7pKIoDWMzSDpSXwrjqgseFqRHTkoUyQqNARHELXoxwv1qGoC 0LYy+fRMCi54wcg87RWo1gCjyGhTfpaQVA== X-Google-Smtp-Source: ABdhPJzIu53i+hoVd9Ngr9ybt0u7H25mEZU+kuIkiFrLep98sVOIIkcpRt6BfJXfbtsVLlRksnUejg== X-Received: by 2002:a2e:bc1b:: with SMTP id b27mr24175465ljf.91.1637838188551; Thu, 25 Nov 2021 03:03:08 -0800 (PST) From: Oleksandr Andrushchenko To: xen-devel@lists.xenproject.org Cc: julien@xen.org, sstabellini@kernel.org, oleksandr_tyshchenko@epam.com, volodymyr_babchuk@epam.com, Artem_Mygaiev@epam.com, roger.pau@citrix.com, jbeulich@suse.com, andrew.cooper3@citrix.com, george.dunlap@citrix.com, paul@xen.org, bertrand.marquis@arm.com, rahul.singh@arm.com, Oleksandr Andrushchenko Subject: [PATCH v5 11/14] vpci: add initial support for virtual PCI bus topology Date: Thu, 25 Nov 2021 13:02:48 +0200 Message-Id: <20211125110251.2877218-12-andr2000@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211125110251.2877218-1-andr2000@gmail.com> References: <20211125110251.2877218-1-andr2000@gmail.com> MIME-Version: 1.0 From: Oleksandr Andrushchenko Assign SBDF to the PCI devices being passed through with bus 0. The resulting topology is where PCIe devices reside on the bus 0 of the root complex itself (embedded endpoints). This implementation is limited to 32 devices which are allowed on a single PCI bus. Please note, that at the moment only function 0 of a multifunction device can be passed through. Signed-off-by: Oleksandr Andrushchenko --- Since v4: - moved and re-worked guest sbdf initializers - s/set_bit/__set_bit - s/clear_bit/__clear_bit - minor comment fix s/Virtual/Guest/ - added VPCI_MAX_VIRT_DEV constant (PCI_SLOT(~0) + 1) which will be used later for counting the number of MMIO handlers required for a guest (Julien) Since v3: - make use of VPCI_INIT - moved all new code to vpci.c which belongs to it - changed open-coded 31 to PCI_SLOT(~0) - added comments and code to reject multifunction devices with functions other than 0 - updated comment about vpci_dev_next and made it unsigned int - implement roll back in case of error while assigning/deassigning devices - s/dom%pd/%pd Since v2: - remove casts that are (a) malformed and (b) unnecessary - add new line for better readability - remove CONFIG_HAS_VPCI_GUEST_SUPPORT ifdef's as the relevant vPCI functions are now completely gated with this config - gate common code with CONFIG_HAS_VPCI_GUEST_SUPPORT New in v2 --- xen/drivers/vpci/vpci.c | 51 +++++++++++++++++++++++++++++++++++++++++ xen/include/xen/sched.h | 8 +++++++ xen/include/xen/vpci.h | 11 +++++++++ 3 files changed, 70 insertions(+) diff --git a/xen/drivers/vpci/vpci.c b/xen/drivers/vpci/vpci.c index 98b12a61be6f..c2fb4d4db233 100644 --- a/xen/drivers/vpci/vpci.c +++ b/xen/drivers/vpci/vpci.c @@ -114,6 +114,9 @@ int vpci_add_handlers(struct pci_dev *pdev) spin_lock(&pdev->vpci_lock); pdev->vpci = vpci; INIT_LIST_HEAD(&pdev->vpci->handlers); +#ifdef CONFIG_HAS_VPCI_GUEST_SUPPORT + pdev->vpci->guest_sbdf.sbdf = ~0; +#endif header = &pdev->vpci->header; for ( i = 0; i < ARRAY_SIZE(header->bars); i++ ) @@ -145,6 +148,53 @@ int vpci_add_handlers(struct pci_dev *pdev) } #ifdef CONFIG_HAS_VPCI_GUEST_SUPPORT +int vpci_add_virtual_device(struct pci_dev *pdev) +{ + struct domain *d = pdev->domain; + pci_sbdf_t sbdf = { 0 }; + unsigned long new_dev_number; + + /* + * Each PCI bus supports 32 devices/slots at max or up to 256 when + * there are multi-function ones which are not yet supported. + */ + if ( pdev->info.is_extfn ) + { + gdprintk(XENLOG_ERR, "%pp: only function 0 passthrough supported\n", + &pdev->sbdf); + return -EOPNOTSUPP; + } + + new_dev_number = find_first_zero_bit(&d->vpci_dev_assigned_map, + VPCI_MAX_VIRT_DEV); + if ( new_dev_number >= VPCI_MAX_VIRT_DEV ) + return -ENOSPC; + + __set_bit(new_dev_number, &d->vpci_dev_assigned_map); + + /* + * Both segment and bus number are 0: + * - we emulate a single host bridge for the guest, e.g. segment 0 + * - with bus 0 the virtual devices are seen as embedded + * endpoints behind the root complex + * + * TODO: add support for multi-function devices. + */ + sbdf.devfn = PCI_DEVFN(new_dev_number, 0); + pdev->vpci->guest_sbdf = sbdf; + + return 0; + +} +REGISTER_VPCI_INIT(vpci_add_virtual_device, VPCI_PRIORITY_MIDDLE); + +static void vpci_remove_virtual_device(struct domain *d, + const struct pci_dev *pdev) +{ + __clear_bit(pdev->vpci->guest_sbdf.dev, &d->vpci_dev_assigned_map); + pdev->vpci->guest_sbdf.sbdf = ~0; +} + /* Notify vPCI that device is assigned to guest. */ int vpci_assign_device(struct domain *d, struct pci_dev *pdev) { @@ -171,6 +221,7 @@ int vpci_deassign_device(struct domain *d, struct pci_dev *pdev) return 0; spin_lock(&pdev->vpci_lock); + vpci_remove_virtual_device(d, pdev); vpci_remove_device_handlers_locked(pdev); spin_unlock(&pdev->vpci_lock); diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h index 28146ee404e6..10bff103317c 100644 --- a/xen/include/xen/sched.h +++ b/xen/include/xen/sched.h @@ -444,6 +444,14 @@ struct domain #ifdef CONFIG_HAS_PCI struct list_head pdev_list; +#ifdef CONFIG_HAS_VPCI_GUEST_SUPPORT + /* + * The bitmap which shows which device numbers are already used by the + * virtual PCI bus topology and is used to assign a unique SBDF to the + * next passed through virtual PCI device. + */ + unsigned long vpci_dev_assigned_map; +#endif #endif #ifdef CONFIG_HAS_PASSTHROUGH diff --git a/xen/include/xen/vpci.h b/xen/include/xen/vpci.h index 18319fc329f9..e5258bd7ce90 100644 --- a/xen/include/xen/vpci.h +++ b/xen/include/xen/vpci.h @@ -21,6 +21,13 @@ typedef int vpci_register_init_t(struct pci_dev *dev); #define VPCI_ECAM_BDF(addr) (((addr) & 0x0ffff000) >> 12) +/* + * Maximum number of devices supported by the virtual bus topology: + * each PCI bus supports 32 devices/slots at max or up to 256 when + * there are multi-function ones which are not yet supported. + */ +#define VPCI_MAX_VIRT_DEV (PCI_SLOT(~0) + 1) + #define REGISTER_VPCI_INIT(x, p) \ static vpci_register_init_t *const x##_entry \ __used_section(".data.vpci." p) = x @@ -143,6 +150,10 @@ struct vpci { struct vpci_arch_msix_entry arch; } entries[]; } *msix; +#ifdef CONFIG_HAS_VPCI_GUEST_SUPPORT + /* Guest SBDF of the device. */ + pci_sbdf_t guest_sbdf; +#endif #endif };