From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36035) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZLCdq-0000zD-4O for qemu-devel@nongnu.org; Fri, 31 Jul 2015 11:54:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZLCdi-0005uv-Ha for qemu-devel@nongnu.org; Fri, 31 Jul 2015 11:54:38 -0400 Received: from mail-wi0-f169.google.com ([209.85.212.169]:36631) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZLCdi-0005ul-9X for qemu-devel@nongnu.org; Fri, 31 Jul 2015 11:54:30 -0400 Received: by wicgj17 with SMTP id gj17so23709349wic.1 for ; Fri, 31 Jul 2015 08:54:29 -0700 (PDT) From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Fri, 31 Jul 2015 16:53:59 +0100 Message-Id: <1438358041-18021-10-git-send-email-alex.bennee@linaro.org> In-Reply-To: <1438358041-18021-1-git-send-email-alex.bennee@linaro.org> References: <1438358041-18021-1-git-send-email-alex.bennee@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [kvm-unit-tests PATCH v5 09/11] arm: query /dev/kvm for maximum vcpus List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: mttcg@listserver.greensocs.com, mark.burton@greensocs.com, fred.konrad@greensocs.com Cc: peter.maydell@linaro.org, drjones@redhat.com, =?UTF-8?q?Alex=20Benn=C3=A9e?= , kvm@vger.kernel.org, a.spyridakis@virtualopensystems.com, claudio.fontana@huawei.com, a.rigo@virtualopensystems.com, qemu-devel@nongnu.org, =?UTF-8?q?Alex=20Benn=C3=A9e?= From: Alex Bennée The previous $(getconf _NPROCESSORS_CONF) isn't correct as the default maximum VCPU configuration is 4 on arm64 machines which typically have more actual cores. This introduces a simple utility program to query the KVM capabilities and use the correct maximum number of vcpus. [FOR DISCUSSION: this fails on TCG which could use _NPROCESSORS_CONF] Signed-off-by: Alex Bennée --- arm/unittests.cfg | 10 +++++----- arm/utils/kvm-query.c | 41 +++++++++++++++++++++++++++++++++++++++++ config/config-arm-common.mak | 8 +++++++- 3 files changed, 53 insertions(+), 6 deletions(-) create mode 100644 arm/utils/kvm-query.c diff --git a/arm/unittests.cfg b/arm/unittests.cfg index 19d72ad..7a3a32b 100644 --- a/arm/unittests.cfg +++ b/arm/unittests.cfg @@ -32,30 +32,30 @@ groups = selftest # Test SMP support [selftest::smp] file = selftest.flat -smp = $(getconf _NPROCESSORS_CONF) +smp = $(./arm/utils/kvm-query max_vcpu) extra_params = -append 'smp' groups = selftest # TLB Torture Tests [tlbflush::all_other] file = tlbflush-test.flat -smp = $(getconf _NPROCESSORS_CONF) +smp = $(./arm/utils/kvm-query max_vcpu) groups = tlbflush [tlbflush::page_other] file = tlbflush-test.flat -smp = $(getconf _NPROCESSORS_CONF) +smp = $(./arm/utils/kvm-query max_vcpu) extra_params = -append 'page' groups = tlbflush [tlbflush::all_self] file = tlbflush-test.flat -smp = $(getconf _NPROCESSORS_CONF) +smp = $(./arm/utils/kvm-query max_vcpu) extra_params = -append 'self' groups = tlbflush [tlbflush::page_self] file = tlbflush-test.flat -smp = $(getconf _NPROCESSORS_CONF) +smp = $(./arm/utils/kvm-query max_vcpu) extra_params = -append 'page self' groups = tlbflush diff --git a/arm/utils/kvm-query.c b/arm/utils/kvm-query.c new file mode 100644 index 0000000..4f979b1 --- /dev/null +++ b/arm/utils/kvm-query.c @@ -0,0 +1,41 @@ +/* + * kvm-query.c + * + * A simple utility to query KVM capabilities. + */ + +#include +#include +#include +#include +#include + +#include +#include + +#include + +int get_max_vcpu(void) +{ + int fd = open("/dev/kvm", O_RDWR); + if (fd>0) { + int ret = ioctl(fd, KVM_CHECK_EXTENSION, KVM_CAP_MAX_VCPUS); + printf("%d\n", ret > 0 ? ret : 0); + close(fd); + return 0; + } else { + return -1; + } +} + +int main(int argc, char **argv) +{ + for (int i=0; i