Message ID | 20191101202502.31750-4-andrew.cooper3@citrix.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | Fix PV shim ballooning problems | expand |
On 01.11.2019 21:25, Andrew Cooper wrote: > From: Sergey Dyasli <sergey.dyasli@citrix.com> > > Converting a guest from PV to PV-in-PVH makes the guest to have 384k > less memory, which may confuse guest's balloon driver. This happens > because Xen unconditionally reserves 640k - 1M region in E820 despite > the fact that it's really a usable RAM in PVH boot mode. > > Fix this by skipping region type change in virtualised environments, > trusting whatever memory map our hypervisor has provided. > > Signed-off-by: Sergey Dyasli <sergey.dyasli@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
diff --git a/xen/arch/x86/e820.c b/xen/arch/x86/e820.c index 8e8a2c4e1b..082f9928a1 100644 --- a/xen/arch/x86/e820.c +++ b/xen/arch/x86/e820.c @@ -318,9 +318,9 @@ static int __init copy_e820_map(struct e820entry * biosmap, unsigned int nr_map) /* * Some BIOSes claim RAM in the 640k - 1M region. - * Not right. Fix it up. + * Not right. Fix it up, but only when running on bare metal. */ - if (type == E820_RAM) { + if (!cpu_has_hypervisor && type == E820_RAM) { if (start < 0x100000ULL && end > 0xA0000ULL) { if (start < 0xA0000ULL) add_memory_region(start, 0xA0000ULL-start, type);