From 647f41c70db5a47e3376d2ad0892e43814aaf4db Mon Sep 17 00:00:00 2001 From: "kfraser@localhost.localdomain" Date: Mon, 6 Aug 2007 11:16:14 +0100 Subject: hvm: Fix PV-on-HVM drivers to not execuite hypercall page while it is being re-initialised. Signed-off-by: Edwin Zhai --- unmodified_drivers/linux-2.6/platform-pci/machine_reboot.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'unmodified_drivers') diff --git a/unmodified_drivers/linux-2.6/platform-pci/machine_reboot.c b/unmodified_drivers/linux-2.6/platform-pci/machine_reboot.c index 15ceef8da6..bd58d2ceb5 100644 --- a/unmodified_drivers/linux-2.6/platform-pci/machine_reboot.c +++ b/unmodified_drivers/linux-2.6/platform-pci/machine_reboot.c @@ -11,6 +11,12 @@ struct ap_suspend_info { atomic_t nr_spinning; }; +/* + * Use a rwlock to protect the hypercall page from being executed in AP context + * while the BSP is re-initializing it after restore. + */ +static DEFINE_RWLOCK(suspend_lock); + /* * Spinning prevents, for example, APs touching grant table entries while * the shared grant table is not mapped into the address space imemdiately @@ -27,7 +33,9 @@ static void ap_suspend(void *_info) while (info->do_spin) { cpu_relax(); + read_lock(&suspend_lock); HYPERVISOR_yield(); + read_unlock(&suspend_lock); } mb(); @@ -43,7 +51,9 @@ static int bp_suspend(void) suspend_cancelled = HYPERVISOR_shutdown(SHUTDOWN_suspend); if (!suspend_cancelled) { + write_lock(&suspend_lock); platform_pci_resume(); + write_unlock(&suspend_lock); gnttab_resume(); irq_resume(); } -- cgit v1.2.3