linux-kernel - Re: [PATCH v6 0/3] LoongArch: KVM: Add Binary Translation extension support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAAhV-H6dFBJ+dQE7qzK8aiTjx8NFJtzPWzEGpJ8dm7v4ExD8Ow@mail.gmail.com>
Date: Wed, 28 Aug 2024 10:08:30 +0800
From: Huacai Chen <chenhuacai@...nel.org>
To: Bibo Mao <maobibo@...ngson.cn>
Cc: Tianrui Zhao <zhaotianrui@...ngson.cn>, WANG Xuerui <kernel@...0n.name>, kvm@...r.kernel.org, 
	loongarch@...ts.linux.dev, linux-kernel@...r.kernel.org, 
	Jiaxun Yang <jiaxun.yang@...goat.com>
Subject: Re: [PATCH v6 0/3] LoongArch: KVM: Add Binary Translation extension support

Hi, Bibo,

I have consulted with Jiaxun offline, and he has tried his best to
propose a "scratch vcpu" solution. But unfortunately that solution is
too difficult to implement and he has nearly given up.

So the solution in this series seems the best one, and I will queue it
for loongarch-kvm now.

Huacai

On Tue, Jul 30, 2024 at 3:57 PM Bibo Mao <maobibo@...ngson.cn> wrote:
>
> Loongson Binary Translation (LBT) is used to accelerate binary
> translation, which contains 4 scratch registers (scr0 to scr3), x86/ARM
> eflags (eflags) and x87 fpu stack pointer (ftop).
>
> Like FPU extension, here lately enabling method is used for LBT. LBT
> context is saved/restored during vcpu context switch path.
>
> Also this patch set LBT capability detection, and LBT register get and set
> interface for userspace vmm, so that vm supports migration with BT
> extension.
>
> ---
> v5 ... v6:
>   1. Solve compiling issue with function kvm_get_one_reg() and
>      kvm_set_one_reg().
>
> v4 ... v5:
>   1. Add feature detection for LSX/LASX from vm side, previously
>      LSX/LASX feature is detected from vcpu ioctl command, now both
>      methods are supported.
>
> v3 ... v4:
>   1. Merge LBT feature detection for VM and VCPU into one patch.
>   2. Move function declaration such as kvm_lose_lbt()/kvm_check_fcsr()/
>      kvm_enable_lbt_fpu() from header file to c file, since it is only
>      used in one c file.
>
> v2 ... v3:
>   1. Split KVM_LOONGARCH_VM_FEAT_LBT capability checking into three
>      sub-features, KVM_LOONGARCH_VM_FEAT_X86BT/KVM_LOONGARCH_VM_FEAT_ARMBT
>      and KVM_LOONGARCH_VM_FEAT_MIPSBT. Return success only if host
>      supports the sub-feature.
>
> v1 ... v2:
>   1. With LBT register read or write interface to userpace, replace
>      device attr method with KVM_GET_ONE_REG method, since lbt register is
>      vcpu register and can be added in kvm_reg_list in future.
>   2. Add vm device attr ctrl marcro KVM_LOONGARCH_VM_FEAT_CTRL, it is
>      used to get supported LBT feature before vm or vcpu is created.
> ---
> Bibo Mao (3):
>   LoongArch: KVM: Add HW Binary Translation extension support
>   LoongArch: KVM: Add LBT feature detection function
>   LoongArch: KVM: Add vm migration support for LBT registers
>
>  arch/loongarch/include/asm/kvm_host.h |   8 ++
>  arch/loongarch/include/asm/kvm_vcpu.h |   6 ++
>  arch/loongarch/include/uapi/asm/kvm.h |  17 ++++
>  arch/loongarch/kvm/exit.c             |   9 ++
>  arch/loongarch/kvm/vcpu.c             | 128 +++++++++++++++++++++++++-
>  arch/loongarch/kvm/vm.c               |  52 ++++++++++-
>  6 files changed, 218 insertions(+), 2 deletions(-)
>
>
> base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b
> --
> 2.39.3
>
>