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authorLinus Torvalds <torvalds@linux-foundation.org>2018-10-30 09:31:07 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-10-30 09:31:07 -0700
commit5b4c0d87de2d4932354ebcf118677c94533f9a01 (patch)
tree292a9d90deaa4fc373bf8bb63c48117cbbc96fee /arch/x86
parentc2101d01826480755f2bd9f3dd5e36757be61e23 (diff)
parent7a048cec598e1761cdcd63eb3a3c6e390b7661c7 (diff)
downloadlinux-5b4c0d87de2d4932354ebcf118677c94533f9a01.tar.bz2
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.c4
-rw-r--r--arch/x86/xen/spinlock.c33
-rw-r--r--arch/x86/xen/xen-pvh.S2
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,