Linux KVM/arm64 development list
 help / color / mirror / Atom feed
From: Mark Brown <broonie@kernel.org>
To: Andre Przywara <andre.przywara@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	linux-kernel@vger.kernel.org,
	Catalin Marinas <catalin.marinas@arm.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	Russell King <linux@armlinux.org.uk>,
	Ard Biesheuvel <ardb@kernel.org>,
	Sudeep Holla <sudeep.holla@arm.com>,
	Will Deacon <will@kernel.org>,
	kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 4/5] arm64: Add support for SMCCC TRNG entropy source
Date: Thu, 5 Nov 2020 13:41:42 +0000	[thread overview]
Message-ID: <20201105134142.GA4856@sirena.org.uk> (raw)
In-Reply-To: <20201105125656.25259-5-andre.przywara@arm.com>


[-- Attachment #1.1: Type: text/plain, Size: 643 bytes --]

On Thu, Nov 05, 2020 at 12:56:55PM +0000, Andre Przywara wrote:

>  static inline bool __must_check arch_get_random_seed_int(unsigned int *v)
>  {
> +	struct arm_smccc_res res;
>  	unsigned long val;
> -	bool ok = arch_get_random_seed_long(&val);
>  
> -	*v = val;
> -	return ok;
> +	if (cpus_have_const_cap(ARM64_HAS_RNG)) {
> +		if (arch_get_random_seed_long(&val)) {
> +			*v = val;
> +			return true;
> +		}
> +		return false;
> +	}

It isn't obvious to me why we don't fall through to trying the SMCCC
TRNG here if for some reason the v8.5-RNG didn't give us something.
Definitely an obscure possibility but still...

[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

[-- Attachment #2: Type: text/plain, Size: 151 bytes --]

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

  reply	other threads:[~2020-11-05 13:41 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-05 12:56 [PATCH v2 0/5] ARM: arm64: Add SMCCC TRNG entropy service Andre Przywara
2020-11-05 12:56 ` [PATCH v2 1/5] firmware: smccc: Add SMCCC TRNG function call IDs Andre Przywara
2020-11-05 12:56 ` [PATCH v2 2/5] firmware: smccc: Introduce SMCCC TRNG framework Andre Przywara
2020-11-05 12:56 ` [PATCH v2 3/5] ARM: implement support for SMCCC TRNG entropy source Andre Przywara
2020-11-05 17:15   ` kernel test robot
2020-11-05 17:56     ` André Przywara
2020-11-05 17:15   ` kernel test robot
2020-11-06 15:29   ` Marc Zyngier
2020-11-06 15:30     ` Ard Biesheuvel
2020-11-06 15:35       ` Marc Zyngier
2020-11-05 12:56 ` [PATCH v2 4/5] arm64: Add " Andre Przywara
2020-11-05 13:41   ` Mark Brown [this message]
2020-11-05 14:03     ` Mark Rutland
2020-11-05 14:04       ` Ard Biesheuvel
2020-11-05 14:30         ` Mark Rutland
2020-11-05 14:34           ` Ard Biesheuvel
2020-11-05 14:45             ` Mark Rutland
2020-11-05 14:48             ` Marc Zyngier
2020-11-05 14:29       ` Mark Brown
2020-11-05 14:38         ` Mark Rutland
2020-11-12 16:03           ` André Przywara
2020-11-05 14:30       ` André Przywara
2020-11-05 12:56 ` [PATCH v2 5/5] KVM: arm64: implement the TRNG hypervisor call Andre Przywara
2020-11-05 13:41   ` André Przywara
2020-11-05 14:13   ` Marc Zyngier
2020-11-05 16:19     ` Ard Biesheuvel

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201105134142.GA4856@sirena.org.uk \
    --to=broonie@kernel.org \
    --cc=andre.przywara@arm.com \
    --cc=ardb@kernel.org \
    --cc=catalin.marinas@arm.com \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=linus.walleij@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=lorenzo.pieralisi@arm.com \
    --cc=sudeep.holla@arm.com \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox