From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aurelien Jarno Subject: Re: [PATCH] Fix segfault with ram_size > 4095M without kvm Date: Tue, 23 Feb 2010 18:02:15 +0100 Message-ID: <4B840A17.9050809@aurel32.net> References: <20100223151314.GN17350@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org To: Ryan Harper Return-path: In-Reply-To: <20100223151314.GN17350@us.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org List-Id: kvm.vger.kernel.org Ryan Harper a écrit : > Currently, x86_64-softmmu qemu segfaults when trying to use > 4095M memsize. > This patch adds a simple check and error message (much like the 2047 limit on > 32-bit hosts) on ram_size in the control path after we determine we're > not using kvm > > Upstream qemu-kvm is affected if using the -no-kvm option; this patch address > the segfault there as well. It looks like workarounding the real bug. At some point both i386-softmmu (via PAE) and x86_64-softmmu were able to support > 4GB of memory. I remember adding the support long time ago, and testing it with 32GB of emulated RAM. > Signed-off-by: Ryan Harper > --- > vl.c | 6 ++++++ > 1 files changed, 6 insertions(+), 0 deletions(-) > > diff --git a/vl.c b/vl.c > index db7a178..a659e98 100644 > --- a/vl.c > +++ b/vl.c > @@ -5760,6 +5760,12 @@ int main(int argc, char **argv, char **envp) > fprintf(stderr, "failed to initialize KVM\n"); > exit(1); > } > + } else { > + /* without kvm enabled, we can only support 4095 MB RAM */ > + if (ram_size > (4095UL << 20)) { > + fprintf(stderr, "qemu: without kvm support at most 4095 MB RAM can be simulated\n"); > + exit(1); > + } > } > > if (qemu_init_main_loop()) { -- Aurelien Jarno GPG: 1024D/F1BCDB73 aurelien@aurel32.net http://www.aurel32.net From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Njy9Y-0003WW-P5 for qemu-devel@nongnu.org; Tue, 23 Feb 2010 12:02:32 -0500 Received: from [199.232.76.173] (port=38974 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Njy9X-0003WE-DU for qemu-devel@nongnu.org; Tue, 23 Feb 2010 12:02:31 -0500 Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1Njy9V-0003DM-KU for qemu-devel@nongnu.org; Tue, 23 Feb 2010 12:02:31 -0500 Received: from hall.aurel32.net ([88.191.82.174]:56667) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1Njy9V-0003Ch-BX for qemu-devel@nongnu.org; Tue, 23 Feb 2010 12:02:29 -0500 Message-ID: <4B840A17.9050809@aurel32.net> Date: Tue, 23 Feb 2010 18:02:15 +0100 From: Aurelien Jarno MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH] Fix segfault with ram_size > 4095M without kvm References: <20100223151314.GN17350@us.ibm.com> In-Reply-To: <20100223151314.GN17350@us.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ryan Harper Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org Ryan Harper a écrit : > Currently, x86_64-softmmu qemu segfaults when trying to use > 4095M memsize. > This patch adds a simple check and error message (much like the 2047 limit on > 32-bit hosts) on ram_size in the control path after we determine we're > not using kvm > > Upstream qemu-kvm is affected if using the -no-kvm option; this patch address > the segfault there as well. It looks like workarounding the real bug. At some point both i386-softmmu (via PAE) and x86_64-softmmu were able to support > 4GB of memory. I remember adding the support long time ago, and testing it with 32GB of emulated RAM. > Signed-off-by: Ryan Harper > --- > vl.c | 6 ++++++ > 1 files changed, 6 insertions(+), 0 deletions(-) > > diff --git a/vl.c b/vl.c > index db7a178..a659e98 100644 > --- a/vl.c > +++ b/vl.c > @@ -5760,6 +5760,12 @@ int main(int argc, char **argv, char **envp) > fprintf(stderr, "failed to initialize KVM\n"); > exit(1); > } > + } else { > + /* without kvm enabled, we can only support 4095 MB RAM */ > + if (ram_size > (4095UL << 20)) { > + fprintf(stderr, "qemu: without kvm support at most 4095 MB RAM can be simulated\n"); > + exit(1); > + } > } > > if (qemu_init_main_loop()) { -- Aurelien Jarno GPG: 1024D/F1BCDB73 aurelien@aurel32.net http://www.aurel32.net