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