Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-22 Thread Baoquan He
On 04/22/20 at 12:05pm, David Hildenbrand wrote: > On 22.04.20 11:57, Baoquan He wrote: > > On 04/22/20 at 11:24am, David Hildenbrand wrote: > >> On 22.04.20 11:17, Baoquan He wrote: > >>> On 04/21/20 at 03:29pm, David Hildenbrand wrote: > >> ACPI SRAT is embeded into efi, need read out the rsd

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-22 Thread David Hildenbrand
On 22.04.20 11:57, Baoquan He wrote: > On 04/22/20 at 11:24am, David Hildenbrand wrote: >> On 22.04.20 11:17, Baoquan He wrote: >>> On 04/21/20 at 03:29pm, David Hildenbrand wrote: >> ACPI SRAT is embeded into efi, need read out the rsdp pointer. If we >> don't >> pass the efi, it won'

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-22 Thread Baoquan He
On 04/22/20 at 11:24am, David Hildenbrand wrote: > On 22.04.20 11:17, Baoquan He wrote: > > On 04/21/20 at 03:29pm, David Hildenbrand wrote: > ACPI SRAT is embeded into efi, need read out the rsdp pointer. If we > don't > pass the efi, it won't get the SRAT table correctly, if I rem

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-22 Thread David Hildenbrand
On 22.04.20 11:17, Baoquan He wrote: > On 04/21/20 at 03:29pm, David Hildenbrand wrote: ACPI SRAT is embeded into efi, need read out the rsdp pointer. If we don't pass the efi, it won't get the SRAT table correctly, if I remember correctly. Yeah, I remeber kvm guest can get memory ho

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-22 Thread Baoquan He
On 04/21/20 at 03:29pm, David Hildenbrand wrote: > >> ACPI SRAT is embeded into efi, need read out the rsdp pointer. If we don't > >> pass the efi, it won't get the SRAT table correctly, if I remember > >> correctly. Yeah, I remeber kvm guest can get memory hotplugged with > >> ACPI only, this won'

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-21 Thread David Hildenbrand
>> b) "kexec -s -l" seems to work fine. For now, the kernel does not seem >> to get placed on virtio-mem memory (pure luck due to the left-to-right >> search). Memory added by virtio-mem is not getting added to the e820 >> map. Once the virtio-mem driver comes back up in the kexec kernel, the >>

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-21 Thread Eric W. Biederman
David Hildenbrand writes: >>> ACPI SRAT is embeded into efi, need read out the rsdp pointer. If we don't >>> pass the efi, it won't get the SRAT table correctly, if I remember >>> correctly. Yeah, I remeber kvm guest can get memory hotplugged with >>> ACPI only, this won't happen on bare metal th

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-21 Thread David Hildenbrand
On 21.04.20 15:29, David Hildenbrand wrote: >>> ACPI SRAT is embeded into efi, need read out the rsdp pointer. If we don't >>> pass the efi, it won't get the SRAT table correctly, if I remember >>> correctly. Yeah, I remeber kvm guest can get memory hotplugged with >>> ACPI only, this won't happen

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-21 Thread David Hildenbrand
>> ACPI SRAT is embeded into efi, need read out the rsdp pointer. If we don't >> pass the efi, it won't get the SRAT table correctly, if I remember >> correctly. Yeah, I remeber kvm guest can get memory hotplugged with >> ACPI only, this won't happen on bare metal though. Need check carefully. >>

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-16 Thread David Hildenbrand
>> kexec_walk_memblock() has the option for "kbuf->top_down". Only >> kexec_walk_resources() seems to ignore it. > > Yeah, that top down searching is done in a found low mem area. Means > firstly search an available region bottom up, then put kernel top down > in that region. The reason is our iom

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-16 Thread Baoquan He
On 04/16/20 at 04:09pm, David Hildenbrand wrote: > >>> Sounds doable to me, and not complicated. > >>> > images. It would apply to > > - arm64 and filter out all hotadded memory (IIRC, only boot memory can > be used). > >>> > >>> Do you mean hot added memory after boot can't b

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-16 Thread David Hildenbrand
>>> Sounds doable to me, and not complicated. >>> images. It would apply to - arm64 and filter out all hotadded memory (IIRC, only boot memory can be used). >>> >>> Do you mean hot added memory after boot can't be recognized and added >>> into system RAM on arm64? >> >> See pa

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-16 Thread Baoquan He
On 04/16/20 at 03:31pm, David Hildenbrand wrote: > > Not sure if I get the notifier idea clearly. If you mean > > > > 1) Add a common function to pick memory in unmovable zone; > > Not strictly required IMHO. But, minor detail. > > > 2) Let DLPAR, balloon register with notifier; > > Yeah, or v

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-16 Thread David Hildenbrand
> Not sure if I get the notifier idea clearly. If you mean > > 1) Add a common function to pick memory in unmovable zone; Not strictly required IMHO. But, minor detail. > 2) Let DLPAR, balloon register with notifier; Yeah, or virtio-mem, or any other technology that adds/removes memory dynamic

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-14 Thread Baoquan He
On 04/14/20 at 04:49pm, David Hildenbrand wrote: > > The root cause is kexec-ed kernel is targeted at hotpluggable memory > > region. Just avoiding the movable area can fix it. In kexec_file_load(), > > just checking or picking those unmovable region to put kernel/initrd in > > func

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-14 Thread David Hildenbrand
On 14.04.20 16:39, Baoquan He wrote: > On 04/14/20 at 11:37am, David Hildenbrand wrote: >> On 14.04.20 11:22, Baoquan He wrote: >>> On 04/14/20 at 10:00am, David Hildenbrand wrote: On 14.04.20 08:40, Baoquan He wrote: > On 04/13/20 at 08:15am, Eric W. Biederman wrote: >> Baoquan He wr

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-14 Thread Baoquan He
On 04/14/20 at 11:37am, David Hildenbrand wrote: > On 14.04.20 11:22, Baoquan He wrote: > > On 04/14/20 at 10:00am, David Hildenbrand wrote: > >> On 14.04.20 08:40, Baoquan He wrote: > >>> On 04/13/20 at 08:15am, Eric W. Biederman wrote: > Baoquan He writes: > > > On 04/12/20 at 02:5

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-14 Thread David Hildenbrand
On 14.04.20 11:22, Baoquan He wrote: > On 04/14/20 at 10:00am, David Hildenbrand wrote: >> On 14.04.20 08:40, Baoquan He wrote: >>> On 04/13/20 at 08:15am, Eric W. Biederman wrote: Baoquan He writes: > On 04/12/20 at 02:52pm, Eric W. Biederman wrote: >> >> The only benefit of

Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image

2020-04-14 Thread Baoquan He
On 04/14/20 at 10:00am, David Hildenbrand wrote: > On 14.04.20 08:40, Baoquan He wrote: > > On 04/13/20 at 08:15am, Eric W. Biederman wrote: > >> Baoquan He writes: > >> > >>> On 04/12/20 at 02:52pm, Eric W. Biederman wrote: > > The only benefit of kexec_file_load is that it is simple en