linux-kernel - Re: [PATCH v3 1/7] arm64: hyperv: Use SMC to detect hypervisor presence

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 for Android: free password hash cracker in your pocket

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

Message-ID: <Zq2GGfsHjpoacdy_@liuwe-devbox-debian-v2>
Date: Sat, 3 Aug 2024 01:21:29 +0000
From: Wei Liu <wei.liu@...nel.org>
To: Roman Kisel <romank@...ux.microsoft.com>
Cc: arnd@...db.de, bhelgaas@...gle.com, bp@...en8.de,
	catalin.marinas@....com, dave.hansen@...ux.intel.com,
	decui@...rosoft.com, haiyangz@...rosoft.com, hpa@...or.com,
	kw@...ux.com, kys@...rosoft.com, lenb@...nel.org,
	lpieralisi@...nel.org, mingo@...hat.com, rafael@...nel.org,
	robh@...nel.org, tglx@...utronix.de, wei.liu@...nel.org,
	will@...nel.org, linux-acpi@...r.kernel.org,
	linux-arch@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-pci@...r.kernel.org, x86@...nel.org, apais@...rosoft.com,
	benhill@...rosoft.com, ssengar@...rosoft.com,
	sunilmut@...rosoft.com, vdso@...bites.dev
Subject: Re: [PATCH v3 1/7] arm64: hyperv: Use SMC to detect hypervisor
 presence

On Fri, Jul 26, 2024 at 03:59:04PM -0700, Roman Kisel wrote:
> The arm64 Hyper-V startup path relies on ACPI to detect
> running under a Hyper-V compatible hypervisor. That
> doesn't work on non-ACPI systems.
> 
> Hoist the ACPI detection logic into a separate function,
> use the new SMC added recently to Hyper-V to use in the
> non-ACPI case.
> 
> Signed-off-by: Roman Kisel <romank@...ux.microsoft.com>

The change looks sensible.

Within one minor comment fixed below:

Acked-by: Wei Liu <wei.liu@...nel.org>

However I would also like to get an Acked-by or reivewed-by from someone
who works on the ARM64 side of things -- Saurabh, Boqun, Srivatsa, and
Jinank?

> ---
>  arch/arm64/hyperv/mshyperv.c      | 36 ++++++++++++++++++++++++++-----
>  arch/arm64/include/asm/mshyperv.h |  5 +++++
>  2 files changed, 36 insertions(+), 5 deletions(-)
> 
[...]
> diff --git a/arch/arm64/include/asm/mshyperv.h b/arch/arm64/include/asm/mshyperv.h
> index a975e1a689dd..a7a3586f7cb1 100644
> --- a/arch/arm64/include/asm/mshyperv.h
> +++ b/arch/arm64/include/asm/mshyperv.h
> @@ -51,4 +51,9 @@ static inline u64 hv_get_msr(unsigned int reg)
>  
>  #include <asm-generic/mshyperv.h>
>  
> +#define ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_0	0x7948734d
> +#define ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_1	0x56726570

Presumably these are ASCII codes for an identifier string, please 
provide comments to explain what they are.

> +#define ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_2	0
> +#define ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_3	0
> +
>  #endif
> -- 
> 2.34.1
>