From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- arch/x86/xen/platform-pci-unplug.c | 210 +++++++++++++++++++++++++++++++++++++ 1 file changed, 210 insertions(+) create mode 100644 arch/x86/xen/platform-pci-unplug.c (limited to 'arch/x86/xen/platform-pci-unplug.c') diff --git a/arch/x86/xen/platform-pci-unplug.c b/arch/x86/xen/platform-pci-unplug.c new file mode 100644 index 000000000..62ac4898d --- /dev/null +++ b/arch/x86/xen/platform-pci-unplug.c @@ -0,0 +1,210 @@ +// SPDX-License-Identifier: GPL-2.0 + +/****************************************************************************** + * platform-pci-unplug.c + * + * Xen platform PCI device driver + * Copyright (c) 2010, Citrix + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include + +#include +#include +#include "xen-ops.h" + +#define XEN_PLATFORM_ERR_MAGIC -1 +#define XEN_PLATFORM_ERR_PROTOCOL -2 +#define XEN_PLATFORM_ERR_BLACKLIST -3 + +/* store the value of xen_emul_unplug after the unplug is done */ +static int xen_platform_pci_unplug; +static int xen_emul_unplug; + +static int check_platform_magic(void) +{ + short magic; + char protocol; + + magic = inw(XEN_IOPORT_MAGIC); + if (magic != XEN_IOPORT_MAGIC_VAL) { + pr_err("Xen Platform PCI: unrecognised magic value\n"); + return XEN_PLATFORM_ERR_MAGIC; + } + + protocol = inb(XEN_IOPORT_PROTOVER); + + pr_debug("Xen Platform PCI: I/O protocol version %d\n", + protocol); + + switch (protocol) { + case 1: + outw(XEN_IOPORT_LINUX_PRODNUM, XEN_IOPORT_PRODNUM); + outl(XEN_IOPORT_LINUX_DRVVER, XEN_IOPORT_DRVVER); + if (inw(XEN_IOPORT_MAGIC) != XEN_IOPORT_MAGIC_VAL) { + pr_err("Xen Platform: blacklisted by host\n"); + return XEN_PLATFORM_ERR_BLACKLIST; + } + break; + default: + pr_warn("Xen Platform PCI: unknown I/O protocol version\n"); + return XEN_PLATFORM_ERR_PROTOCOL; + } + + return 0; +} + +bool xen_has_pv_devices(void) +{ + if (!xen_domain()) + return false; + + /* PV and PVH domains always have them. */ + if (xen_pv_domain() || xen_pvh_domain()) + return true; + + /* And user has xen_platform_pci=0 set in guest config as + * driver did not modify the value. */ + if (xen_platform_pci_unplug == 0) + return false; + + if (xen_platform_pci_unplug & XEN_UNPLUG_NEVER) + return false; + + if (xen_platform_pci_unplug & XEN_UNPLUG_ALL) + return true; + + /* This is an odd one - we are going to run legacy + * and PV drivers at the same time. */ + if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY) + return true; + + /* And the caller has to follow with xen_pv_{disk,nic}_devices + * to be certain which driver can load. */ + return false; +} +EXPORT_SYMBOL_GPL(xen_has_pv_devices); + +static bool __xen_has_pv_device(int state) +{ + /* HVM domains might or might not */ + if (xen_hvm_domain() && (xen_platform_pci_unplug & state)) + return true; + + return xen_has_pv_devices(); +} + +bool xen_has_pv_nic_devices(void) +{ + return __xen_has_pv_device(XEN_UNPLUG_ALL_NICS | XEN_UNPLUG_ALL); +} +EXPORT_SYMBOL_GPL(xen_has_pv_nic_devices); + +bool xen_has_pv_disk_devices(void) +{ + return __xen_has_pv_device(XEN_UNPLUG_ALL_IDE_DISKS | + XEN_UNPLUG_AUX_IDE_DISKS | XEN_UNPLUG_ALL); +} +EXPORT_SYMBOL_GPL(xen_has_pv_disk_devices); + +/* + * This one is odd - it determines whether you want to run PV _and_ + * legacy (IDE) drivers together. This combination is only possible + * under HVM. + */ +bool xen_has_pv_and_legacy_disk_devices(void) +{ + if (!xen_domain()) + return false; + + /* N.B. This is only ever used in HVM mode */ + if (xen_pv_domain()) + return false; + + if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY) + return true; + + return false; +} +EXPORT_SYMBOL_GPL(xen_has_pv_and_legacy_disk_devices); + +void xen_unplug_emulated_devices(void) +{ + int r; + + /* PVH guests don't have emulated devices. */ + if (xen_pvh_domain()) + return; + + /* user explicitly requested no unplug */ + if (xen_emul_unplug & XEN_UNPLUG_NEVER) + return; + /* check the version of the xen platform PCI device */ + r = check_platform_magic(); + /* If the version matches enable the Xen platform PCI driver. + * Also enable the Xen platform PCI driver if the host does + * not support the unplug protocol (XEN_PLATFORM_ERR_MAGIC) + * but the user told us that unplugging is unnecessary. */ + if (r && !(r == XEN_PLATFORM_ERR_MAGIC && + (xen_emul_unplug & XEN_UNPLUG_UNNECESSARY))) + return; + /* Set the default value of xen_emul_unplug depending on whether or + * not the Xen PV frontends and the Xen platform PCI driver have + * been compiled for this kernel (modules or built-in are both OK). */ + if (!xen_emul_unplug) { + if (xen_must_unplug_nics()) { + pr_info("Netfront and the Xen platform PCI driver have " + "been compiled for this kernel: unplug emulated NICs.\n"); + xen_emul_unplug |= XEN_UNPLUG_ALL_NICS; + } + if (xen_must_unplug_disks()) { + pr_info("Blkfront and the Xen platform PCI driver have " + "been compiled for this kernel: unplug emulated disks.\n" + "You might have to change the root device\n" + "from /dev/hd[a-d] to /dev/xvd[a-d]\n" + "in your root= kernel command line option\n"); + xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS; + } + } + /* Now unplug the emulated devices */ + if (!(xen_emul_unplug & XEN_UNPLUG_UNNECESSARY)) + outw(xen_emul_unplug, XEN_IOPORT_UNPLUG); + xen_platform_pci_unplug = xen_emul_unplug; +} + +static int __init parse_xen_emul_unplug(char *arg) +{ + char *p, *q; + int l; + + for (p = arg; p; p = q) { + q = strchr(p, ','); + if (q) { + l = q - p; + q++; + } else { + l = strlen(p); + } + if (!strncmp(p, "all", l)) + xen_emul_unplug |= XEN_UNPLUG_ALL; + else if (!strncmp(p, "ide-disks", l)) + xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS; + else if (!strncmp(p, "aux-ide-disks", l)) + xen_emul_unplug |= XEN_UNPLUG_AUX_IDE_DISKS; + else if (!strncmp(p, "nics", l)) + xen_emul_unplug |= XEN_UNPLUG_ALL_NICS; + else if (!strncmp(p, "unnecessary", l)) + xen_emul_unplug |= XEN_UNPLUG_UNNECESSARY; + else if (!strncmp(p, "never", l)) + xen_emul_unplug |= XEN_UNPLUG_NEVER; + else + pr_warn("unrecognised option '%s' " + "in parameter 'xen_emul_unplug'\n", p); + } + return 0; +} +early_param("xen_emul_unplug", parse_xen_emul_unplug); -- cgit v1.2.3