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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-10-30 19:31:07 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-10-30 19:31:07 +0300 |
| commit | 5b4c0d87de2d4932354ebcf118677c94533f9a01 (patch) | |
| tree | 292a9d90deaa4fc373bf8bb63c48117cbbc96fee /arch/x86 | |
| parent | c2101d01826480755f2bd9f3dd5e36757be61e23 (diff) | |
| parent | 7a048cec598e1761cdcd63eb3a3c6e390b7661c7 (diff) | |
| download | linux-5b4c0d87de2d4932354ebcf118677c94533f9a01.tar.xz | |
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 (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/xen/platform-pci-unplug.c | 4 | ||||
| -rw-r--r-- | arch/x86/xen/spinlock.c | 33 | ||||
| -rw-r--r-- | arch/x86/xen/xen-pvh.S | 2 |
3 files changed, 17 insertions, 22 deletions
diff --git a/arch/x86/xen/platform-pci-unplug.c b/arch/x86/xen/platform-pci-unplug.c index 66ab96a4e2b3..96d7f7d39cb9 100644 --- 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 index 23f6793af88a..441c88262169 100644 --- 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 index b0e471506cd8..1f8825bbaffb 100644 --- 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, |