mbox series

[kvm-unit-tests,v2,00/10] SMP Support for x86 UEFI Tests

Message ID 20220412173407.13637-1-varad.gautam@suse.com (mailing list archive)
Headers show
Series SMP Support for x86 UEFI Tests | expand

Message

Varad Gautam April 12, 2022, 5:33 p.m. UTC 
This series brings multi-vcpu support to UEFI tests on x86.

Most of the necessary AP bringup code already exists within kvm-unit-tests'
cstart64.S, and has now been either rewritten in C or moved to a common location
to be shared between EFI and non-EFI test builds.

A call gate is used to transition from 16-bit to 32-bit mode, since EFI may
not load the 32-bit entrypoint low enough to be reachable from the SIPI vector.

Changes in v2:
- rebase onto kvm-unit-tests@1a4529ce83 + seanjc's percpu apic_ops series [1].
- split some commits for readability.

The series has been tested with this patch [2] which fixes EFI pagetable setup.

Git branch: https://github.com/varadgautam/kvm-unit-tests/commits/ap-boot-v2/
[1] https://lore.kernel.org/all/20220121231852.1439917-1-seanjc@google.com/
[2] https://lore.kernel.org/kvm/20220406123312.12986-1-varad.gautam@suse.com/
v1: https://lore.kernel.org/all/20220408103127.19219-1-varad.gautam@suse.com/

Varad Gautam (10):
  x86: Move ap_init() to smp.c
  x86: Move load_idt() to desc.c
  x86: desc: Split IDT entry setup into a generic helper
  x86: Move load_gdt_tss() to desc.c
  x86: efi: Stop using UEFI-provided stack
  x86: efi: Stop using UEFI-provided %gs for percpu storage
  x86: efi, smp: Transition APs from 16-bit to 32-bit mode
  x86: Move 32-bit bringup routines to start32.S
  x86: efi, smp: Transition APs from 32-bit to 64-bit mode
  x86: Move ap_start64 and save_id to setup.c

 lib/x86/asm/setup.h       |   3 ++
 lib/x86/desc.c            |  39 +++++++++++---
 lib/x86/desc.h            |   3 ++
 lib/x86/setup.c           |  59 ++++++++++++++++-----
 lib/x86/smp.c             |  88 +++++++++++++++++++++++++++++++-
 lib/x86/smp.h             |   1 +
 x86/cstart64.S            | 105 ++------------------------------------
 x86/efi/crt0-efi-x86_64.S |   3 ++
 x86/efi/efistart64.S      |  69 ++++++++++++++++++++-----
 x86/start32.S             | 102 ++++++++++++++++++++++++++++++++++++
 10 files changed, 336 insertions(+), 136 deletions(-)
 create mode 100644 x86/start32.S

Comments

Sean Christopherson April 13, 2022, 7:57 p.m. UTC | #1 
On Tue, Apr 12, 2022, Varad Gautam wrote:
> This series brings multi-vcpu support to UEFI tests on x86.
> 
> Most of the necessary AP bringup code already exists within kvm-unit-tests'
> cstart64.S, and has now been either rewritten in C or moved to a common location
> to be shared between EFI and non-EFI test builds.
> 
> A call gate is used to transition from 16-bit to 32-bit mode, since EFI may
> not load the 32-bit entrypoint low enough to be reachable from the SIPI vector.
> 
> Changes in v2:
> - rebase onto kvm-unit-tests@1a4529ce83 + seanjc's percpu apic_ops series [1].

Thanks for taking on the rebase pain, I appreciate it!

Lots of comments, but mostly minor things to (hopefully) improve readability.  I
belive the mixup with 32-bit targets is the only thing that might get painful.
Varad Gautam April 26, 2022, 11:51 a.m. UTC | #2 
On 4/13/22 9:57 PM, Sean Christopherson wrote:
> On Tue, Apr 12, 2022, Varad Gautam wrote:
>> This series brings multi-vcpu support to UEFI tests on x86.
>>
>> Most of the necessary AP bringup code already exists within kvm-unit-tests'
>> cstart64.S, and has now been either rewritten in C or moved to a common location
>> to be shared between EFI and non-EFI test builds.
>>
>> A call gate is used to transition from 16-bit to 32-bit mode, since EFI may
>> not load the 32-bit entrypoint low enough to be reachable from the SIPI vector.
>>
>> Changes in v2:
>> - rebase onto kvm-unit-tests@1a4529ce83 + seanjc's percpu apic_ops series [1].
> 
> Thanks for taking on the rebase pain, I appreciate it!
> 
> Lots of comments, but mostly minor things to (hopefully) improve readability.  I
> belive the mixup with 32-bit targets is the only thing that might get painful.
> 

I've sent out a v3 at [1] taking in most of your comments. I've only left out the
changes to non-EFI 32-bit asm bringup code (x86/start32.S) and some renames which
I think would better go into a different series to keep this one easier to follow.

[1] https://lore.kernel.org/kvm/20220426114352.1262-1-varad.gautam@suse.com/

Thanks,
Varad