From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony PERARD Subject: [PATCH] firmware: Fix vcpu hotplug race with qemu-xen Date: Mon, 9 Dec 2013 18:30:37 +0000 Message-ID: <1386613837-27399-1-git-send-email-anthony.perard@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Xen Devel Cc: Anthony PERARD , Stefano Stabellini , Ian Jackson , Ian Campbell List-Id: xen-devel@lists.xenproject.org When hotplugging more than one vcpu, some of those vcpus might not be seen as plugged by the guest. By using edged-triggered General-Purpose Event instead of a level-triggered GPE, the race is avoided. This is in sync with how a different QEMU guest is handeling CPU hotplug event. There is more information about why in SeaBIOS's commit 9c6635bd48d39a1d17d0a73df6e577ef6bd0037c. Signed-off-by: Anthony PERARD --- tools/firmware/hvmloader/acpi/mk_dsdt.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/tools/firmware/hvmloader/acpi/mk_dsdt.c b/tools/firmware/hvmloader/acpi/mk_dsdt.c index 996f30b..ecbe4cd 100644 --- a/tools/firmware/hvmloader/acpi/mk_dsdt.c +++ b/tools/firmware/hvmloader/acpi/mk_dsdt.c @@ -220,9 +220,13 @@ int main(int argc, char **argv) pop_block(); - /* Define GPE control method '_L02'. */ + /* Define GPE control method. */ push_block("Scope", "\\_GPE"); - push_block("Method", "_L02"); + if (dm_version == QEMU_XEN) { + push_block("Method", "_E02"); + } else { + push_block("Method", "_L02"); + } stmt("Return", "\\_SB.PRSC()"); pop_block(); pop_block(); -- Anthony PERARD