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commit 5b4c0d87de2d4932354ebcf118677c94533f9a01
parent c2101d01826480755f2bd9f3dd5e36757be61e23
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Tue, 30 Oct 2018 09:31:07 -0700

Merge tag 'for-linus-4.20a-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fixes from Juergen Gross:
 "Only several small fixes and cleanups this time"

* tag 'for-linus-4.20a-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: drop writing error messages to xenstore
  xen/pvh: don't try to unplug emulated devices
  add myself as reviewer for Xen support in Linux
  xen: remove redundant 'default n' from Kconfig
  xen/balloon: Support xend-based toolstack
  xen/pvh: increase early stack size
  xen: make xen_qlock_wait() nestable
  xen: fix race in xen_qlock_wait()
  xen/balloon: Grammar s/Is it/It is/
  xen: Make XEN_BACKEND selectable by DomU

Diffstat:
MMAINTAINERS | 1+
March/x86/xen/platform-pci-unplug.c | 4++++
March/x86/xen/spinlock.c | 33++++++++++++---------------------
March/x86/xen/xen-pvh.S | 2+-
Mdrivers/xen/Kconfig | 13++-----------
Mdrivers/xen/xen-balloon.c | 13++++++++-----
Mdrivers/xen/xenbus/xenbus_client.c | 6++----
7 files changed, 30 insertions(+), 42 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS @@ -16317,6 +16317,7 @@ F: arch/arm64/include/asm/xen/ XEN HYPERVISOR INTERFACE M: Boris Ostrovsky <boris.ostrovsky@oracle.com> M: Juergen Gross <jgross@suse.com> +R: Stefano Stabellini <sstabellini@kernel.org> L: xen-devel@lists.xenproject.org (moderated for non-subscribers) T: git git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git S: Supported diff --git a/arch/x86/xen/platform-pci-unplug.c b/arch/x86/xen/platform-pci-unplug.c @@ -134,6 +134,10 @@ 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; diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c @@ -39,34 +39,25 @@ static void xen_qlock_kick(int cpu) */ static void xen_qlock_wait(u8 *byte, u8 val) { + unsigned long flags; int irq = __this_cpu_read(lock_kicker_irq); /* If kicker interrupts not initialized yet, just spin */ - if (irq == -1) + if (irq == -1 || in_nmi()) return; - /* clear pending */ - xen_clear_irq_pending(irq); - barrier(); - - /* - * We check the byte value after clearing pending IRQ to make sure - * that we won't miss a wakeup event because of the clearing. - * - * The sync_clear_bit() call in xen_clear_irq_pending() is atomic. - * So it is effectively a memory barrier for x86. - */ - if (READ_ONCE(*byte) != val) - return; + /* Guard against reentry. */ + local_irq_save(flags); - /* - * If an interrupt happens here, it will leave the wakeup irq - * pending, which will cause xen_poll_irq() to return - * immediately. - */ + /* If irq pending already clear it. */ + if (xen_test_irq_pending(irq)) { + xen_clear_irq_pending(irq); + } else if (READ_ONCE(*byte) == val) { + /* Block until irq becomes pending (or a spurious wakeup) */ + xen_poll_irq(irq); + } - /* Block until irq becomes pending (or perhaps a spurious wakeup) */ - xen_poll_irq(irq); + local_irq_restore(flags); } static irqreturn_t dummy_handler(int irq, void *dev_id) diff --git a/arch/x86/xen/xen-pvh.S b/arch/x86/xen/xen-pvh.S @@ -170,7 +170,7 @@ canary: .fill 48, 1, 0 early_stack: - .fill 256, 1, 0 + .fill BOOT_STACK_SIZE, 1, 0 early_stack_end: ELFNOTE(Xen, XEN_ELFNOTE_PHYS32_ENTRY, diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig @@ -12,7 +12,6 @@ config XEN_BALLOON config XEN_SELFBALLOONING bool "Dynamically self-balloon kernel memory to target" depends on XEN && XEN_BALLOON && CLEANCACHE && SWAP && XEN_TMEM - default n help Self-ballooning dynamically balloons available kernel memory driven by the current usage of anonymous memory ("committed AS") and @@ -27,7 +26,6 @@ config XEN_SELFBALLOONING config XEN_BALLOON_MEMORY_HOTPLUG bool "Memory hotplug support for Xen balloon driver" - default n depends on XEN_BALLOON && MEMORY_HOTPLUG help Memory hotplug support for Xen balloon driver allows expanding memory @@ -86,7 +84,7 @@ config XEN_SCRUB_PAGES_DEFAULT help Scrub pages before returning them to the system for reuse by other domains. This makes sure that any confidential data - is not accidentally visible to other domains. Is it more + is not accidentally visible to other domains. It is more secure, but slightly less efficient. This can be controlled with xen_scrub_pages=0 parameter and /sys/devices/system/xen_memory/xen_memory0/scrub_pages. @@ -105,8 +103,7 @@ config XEN_DEV_EVTCHN config XEN_BACKEND bool "Backend driver support" - depends on XEN_DOM0 - default y + default XEN_DOM0 help Support for backend device drivers that provide I/O services to other virtual machines. @@ -227,7 +224,6 @@ config XEN_PCIDEV_BACKEND config XEN_PVCALLS_FRONTEND tristate "XEN PV Calls frontend driver" depends on INET && XEN - default n select XEN_XENBUS_FRONTEND help Experimental frontend for the Xen PV Calls protocol @@ -238,7 +234,6 @@ config XEN_PVCALLS_FRONTEND config XEN_PVCALLS_BACKEND bool "XEN PV Calls backend driver" depends on INET && XEN && XEN_BACKEND - default n help Experimental backend for the Xen PV Calls protocol (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It @@ -264,7 +259,6 @@ config XEN_PRIVCMD config XEN_STUB bool "Xen stub drivers" depends on XEN && X86_64 && BROKEN - default n help Allow kernel to install stub drivers, to reserve space for Xen drivers, i.e. memory hotplug and cpu hotplug, and to block native drivers loaded, @@ -275,7 +269,6 @@ config XEN_STUB config XEN_ACPI_HOTPLUG_MEMORY tristate "Xen ACPI memory hotplug" depends on XEN_DOM0 && XEN_STUB && ACPI - default n help This is Xen ACPI memory hotplug. @@ -287,7 +280,6 @@ config XEN_ACPI_HOTPLUG_CPU tristate "Xen ACPI cpu hotplug" depends on XEN_DOM0 && XEN_STUB && ACPI select ACPI_CONTAINER - default n help Xen ACPI cpu enumerating and hotplugging @@ -316,7 +308,6 @@ config XEN_ACPI_PROCESSOR config XEN_MCE_LOG bool "Xen platform mcelog" depends on XEN_DOM0 && X86_64 && X86_MCE - default n help Allow kernel fetching MCE error from Xen platform and converting it into Linux mcelog format for mcelog tools diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c @@ -76,12 +76,15 @@ static void watch_target(struct xenbus_watch *watch, if (!watch_fired) { watch_fired = true; - err = xenbus_scanf(XBT_NIL, "memory", "static-max", "%llu", - &static_max); - if (err != 1) - static_max = new_target; - else + + if ((xenbus_scanf(XBT_NIL, "memory", "static-max", + "%llu", &static_max) == 1) || + (xenbus_scanf(XBT_NIL, "memory", "memory_static_max", + "%llu", &static_max) == 1)) static_max >>= PAGE_SHIFT - 10; + else + static_max = new_target; + target_diff = (xen_pv_domain() || xen_initial_domain()) ? 0 : static_max - balloon_stats.target_pages; } diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c @@ -278,10 +278,8 @@ static void xenbus_va_dev_error(struct xenbus_device *dev, int err, dev_err(&dev->dev, "%s\n", printf_buffer); path_buffer = kasprintf(GFP_KERNEL, "error/%s", dev->nodename); - if (!path_buffer || - xenbus_write(XBT_NIL, path_buffer, "error", printf_buffer)) - dev_err(&dev->dev, "failed to write error node for %s (%s)\n", - dev->nodename, printf_buffer); + if (path_buffer) + xenbus_write(XBT_NIL, path_buffer, "error", printf_buffer); kfree(printf_buffer); kfree(path_buffer);