Re: [Xen-devel] [PATCH for 4.13] x86/shim: don't reserve 640k - 1M region in E820

2019-10-29 Thread Andrew Cooper
On 29/10/2019 10:40, Sergey Dyasli wrote: > On 29/10/2019 10:19, Andrew Cooper wrote: >> On 29/10/2019 10:17, Sergey Dyasli wrote: >>> On 28/10/2019 11:33, Andrew Cooper wrote: For now, how about cpu_has_hypervisor ? Whatever the virtual environment, we should trust the provided memo

Re: [Xen-devel] [PATCH for 4.13] x86/shim: don't reserve 640k - 1M region in E820

2019-10-29 Thread Sergey Dyasli
On 29/10/2019 10:19, Andrew Cooper wrote: > On 29/10/2019 10:17, Sergey Dyasli wrote: >> On 28/10/2019 11:33, Andrew Cooper wrote: >>> For now, how about cpu_has_hypervisor ? >>> >>> Whatever the virtual environment, we should trust the provided memory map. >> Unfortunately, this plan has failed: i

Re: [Xen-devel] [PATCH for 4.13] x86/shim: don't reserve 640k - 1M region in E820

2019-10-29 Thread Andrew Cooper
On 29/10/2019 10:17, Sergey Dyasli wrote: > On 28/10/2019 11:33, Andrew Cooper wrote: >> On 28/10/2019 11:30, Jan Beulich wrote: >>> On 28.10.2019 12:15, Andrew Cooper wrote: On 28/10/2019 11:11, Jan Beulich wrote: > On 28.10.2019 12:08, Sergey Dyasli wrote: >> On 28/10/2019 09:06, Jan

Re: [Xen-devel] [PATCH for 4.13] x86/shim: don't reserve 640k - 1M region in E820

2019-10-29 Thread Sergey Dyasli
On 28/10/2019 11:33, Andrew Cooper wrote: > On 28/10/2019 11:30, Jan Beulich wrote: >> On 28.10.2019 12:15, Andrew Cooper wrote: >>> On 28/10/2019 11:11, Jan Beulich wrote: On 28.10.2019 12:08, Sergey Dyasli wrote: > On 28/10/2019 09:06, Jan Beulich wrote: >> On 28.10.2019 09:56, Serge

Re: [Xen-devel] [PATCH for 4.13] x86/shim: don't reserve 640k - 1M region in E820

2019-10-28 Thread Jan Beulich
On 28.10.2019 12:33, Andrew Cooper wrote: > On 28/10/2019 11:30, Jan Beulich wrote: >> On 28.10.2019 12:15, Andrew Cooper wrote: >>> On 28/10/2019 11:11, Jan Beulich wrote: On 28.10.2019 12:08, Sergey Dyasli wrote: > On 28/10/2019 09:06, Jan Beulich wrote: >> On 28.10.2019 09:56, Serge

Re: [Xen-devel] [PATCH for 4.13] x86/shim: don't reserve 640k - 1M region in E820

2019-10-28 Thread Andrew Cooper
On 28/10/2019 11:30, Jan Beulich wrote: > On 28.10.2019 12:15, Andrew Cooper wrote: >> On 28/10/2019 11:11, Jan Beulich wrote: >>> On 28.10.2019 12:08, Sergey Dyasli wrote: On 28/10/2019 09:06, Jan Beulich wrote: > On 28.10.2019 09:56, Sergey Dyasli wrote: >> Converting a guest from PV

Re: [Xen-devel] [PATCH for 4.13] x86/shim: don't reserve 640k - 1M region in E820

2019-10-28 Thread Jan Beulich
On 28.10.2019 12:15, Andrew Cooper wrote: > On 28/10/2019 11:11, Jan Beulich wrote: >> On 28.10.2019 12:08, Sergey Dyasli wrote: >>> On 28/10/2019 09:06, Jan Beulich wrote: On 28.10.2019 09:56, Sergey Dyasli wrote: > Converting a guest from PV to PV-in-PVH makes the guest to have 384k

Re: [Xen-devel] [PATCH for 4.13] x86/shim: don't reserve 640k - 1M region in E820

2019-10-28 Thread Andrew Cooper
On 28/10/2019 11:11, Jan Beulich wrote: > On 28.10.2019 12:08, Sergey Dyasli wrote: >> On 28/10/2019 09:06, Jan Beulich wrote: >>> On 28.10.2019 09:56, Sergey Dyasli wrote: Converting a guest from PV to PV-in-PVH makes the guest to have 384k less memory, which may confuse guest's balloon

Re: [Xen-devel] [PATCH for 4.13] x86/shim: don't reserve 640k - 1M region in E820

2019-10-28 Thread Jan Beulich
On 28.10.2019 12:08, Sergey Dyasli wrote: > On 28/10/2019 09:06, Jan Beulich wrote: >> On 28.10.2019 09:56, Sergey Dyasli wrote: >>> 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 unconditi

Re: [Xen-devel] [PATCH for 4.13] x86/shim: don't reserve 640k - 1M region in E820

2019-10-28 Thread Sergey Dyasli
On 28/10/2019 09:06, Jan Beulich wrote: > On 28.10.2019 09:56, Sergey Dyasli wrote: >> 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

Re: [Xen-devel] [PATCH for 4.13] x86/shim: don't reserve 640k - 1M region in E820

2019-10-28 Thread Jan Beulich
On 28.10.2019 09:56, Sergey Dyasli wrote: > 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

[Xen-devel] [PATCH for 4.13] x86/shim: don't reserve 640k - 1M region in E820

2019-10-28 Thread Sergey Dyasli
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 the region ty