Xin, Xiaohui
2006-Dec-01 06:08 UTC
[Xen-devel]Is 7G memory good enough for current PAE HVM guest
Some background: We are now debugging the Qemu map cache issue for HVM PAE guest on PAE host. We found that a hardcode limit for shadow2 which we can only support about 7G memory for HVM PAE guest. With the attached workaround and the Qemu map cache patch, we can now support almost 16G memory PAE guest. But it does of course decrease the virtual address space which Xen can map. So it is a question now: Is 7G memory good enough for current PAE HVM guest? And by the way, if a guest requests too much memory, Xen should check it first before creation. Thanks Xiaohui/Dexuan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Keir Fraser
2006-Dec-01 08:08 UTC
Re: [Xen-devel]Is 7G memory good enough for current PAE HVM guest
On 1/12/06 6:08 am, "Xin, Xiaohui" <xiaohui.xin@intel.com> wrote:> Some background: > We are now debugging the Qemu map cache issue for HVM PAE guest on PAE host. > > We found that a hardcode limit for shadow2 which we can only support about 7G > memory for HVM PAE guest. > With the attached workaround and the Qemu map cache patch, we can now support > almost 16G memory PAE guest. > But it does of course decrease the virtual address space which Xen can map. > So it is a question now: Is 7G memory good enough for current PAE HVM guest? > And by the way, if a guest requests too much memory, Xen should check it first > before creation.We should simply check against the 7G limit. Making the memory hole bigger breaks ABI compatibility. I see there are other fixes and cleanups in the patch so I think the bulk of it should be applied anyway. -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel