From: Xi Ruoyao <xry111@xry111.site>
To: maobibo <maobibo@loongson.cn>, WANG Xuerui <kernel@xen0n.name>,
Huacai Chen <chenhuacai@kernel.org>,
Tianrui Zhao <zhaotianrui@loongson.cn>,
Juergen Gross <jgross@suse.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Jonathan Corbet <corbet@lwn.net>
Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org,
virtualization@lists.linux.dev, kvm@vger.kernel.org
Subject: Re: [PATCH v7 3/7] LoongArch: KVM: Add cpucfg area for kvm hypervisor
Date: Tue, 02 Apr 2024 13:34:21 +0800 [thread overview]
Message-ID: <71ab04b76d23497ff63e36dcc05f6580223d22a2.camel@xry111.site> (raw)
In-Reply-To: <d42c7783-3d0a-57fd-fcbe-a1a657255ae4@loongson.cn>
On Tue, 2024-04-02 at 11:34 +0800, maobibo wrote:
> Are you sure that it's impossible to read some data used by the kernel
> internally?
Yes.
> There is another issue, since kernel restore T0-T7 registers and user
> space save T0-T7. Why T0-T7 is scratch registers rather than preserve
> registers like other architecture? What is the advantage if it is
> scratch registers?
I'd say "MIPS legacy." Note that MIPS also does not preserve temp
registers, and MIPS does not have the "info leak" issue as well (or it
should have been assigned a CVE, in all these years).
I do agree maybe it's the time to move away from MIPS legacy and be more
similar to RISC-V etc now...
In Glibc we can condition __SYSCALL_CLOBBERS with #if
__LINUX_KERNEL_VERSION > xxxxxxx to take the advantage.
Huacai, Xuerui, how do you think?
--
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University
next prev parent reply other threads:[~2024-04-02 5:34 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-15 8:07 [PATCH v7 0/7] LoongArch: Add pv ipi support on LoongArch VM Bibo Mao
2024-03-15 8:07 ` [PATCH v7 1/7] LoongArch/smp: Refine some ipi functions on LoongArch platform Bibo Mao
2024-03-15 8:07 ` [PATCH v7 2/7] LoongArch: KVM: Add hypercall instruction emulation support Bibo Mao
2024-03-15 8:07 ` [PATCH v7 3/7] LoongArch: KVM: Add cpucfg area for kvm hypervisor Bibo Mao
2024-03-23 19:02 ` WANG Xuerui
2024-04-02 1:43 ` maobibo
2024-04-02 2:49 ` Xi Ruoyao
2024-04-02 3:04 ` maobibo
2024-04-02 3:34 ` maobibo
2024-04-02 5:34 ` Xi Ruoyao [this message]
2024-03-15 8:07 ` [PATCH v7 4/7] LoongArch: KVM: Add vcpu search support from physical cpuid Bibo Mao
2024-03-15 8:07 ` [PATCH v7 5/7] LoongArch: KVM: Add pv ipi support on kvm side Bibo Mao
2024-03-15 8:10 ` [PATCH v7 6/7] LoongArch: Add pv ipi support on guest kernel side Bibo Mao
2024-03-15 8:11 ` [PATCH v7 7/7] Documentation: KVM: Add hypercall for LoongArch Bibo Mao
2024-03-23 18:40 ` WANG Xuerui
2024-04-02 1:15 ` maobibo
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