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From: David Gibson <david@gibson.dropbear.id.au>
To: Richard Henderson <richard.henderson@linaro.org>
Cc: Ivan Warren <ivan@vmfacility.fr>,
	qemu-ppc@nongnu.org, qemu-devel@nongnu.org
Subject: Re: [PATCH v4 07/17] target/ppc: Disconnect hflags from MSR
Date: Wed, 24 Mar 2021 12:42:07 +1100	[thread overview]
Message-ID: <YFqY7zsmRHswtwjd@yekko.fritz.box> (raw)
In-Reply-To: <77f791b0-ae68-a646-c38d-484fc0d96961@linaro.org>

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On Tue, Mar 23, 2021 at 11:04:03AM -0600, Richard Henderson wrote:
> On 3/22/21 5:54 PM, David Gibson wrote:
> > On Mon, Mar 22, 2021 at 10:55:46AM -0600, Richard Henderson wrote:
> > > On 3/21/21 9:52 PM, David Gibson wrote:
> > > > > +/*
> > > > > + * Bits for env->hflags.
> > > > > + *
> > > > > + * Most of these bits overlap with corresponding bits in MSR,
> > > > > + * but some come from other sources.  Be cautious when modifying.
> > > > 
> > > > Yeah.. I'm not sure "be cautious" is enough of a warning.  The exact
> > > > value of some but not all of these flags must equal that for the
> > > > corresponding MSR bits, which is terrifyingly subtle.
> > > 
> > > Fair.  How about, for the comment here, "This is validated in hreg_compute_hflags."
> > > 
> > > > > +    /* Some bits come straight across from MSR. */
> > > > > +    msr_mask = ((1 << MSR_LE) | (1 << MSR_PR) |
> > > > > +                (1 << MSR_DR) | (1 << MSR_IR) |
> > > > > +                (1 << MSR_FP) | (1 << MSR_SA) | (1 << MSR_AP));
> > > 
> > > Here, and in every other spot within this function where we manipulate msr_mask,
> > > 
> > >      QEMU_BUILD_BUG_ON(MSR_LE != HFLAGS_LE);
> > 
> > Seems reasonable.
> 
> Hah.  Your paranoia was well-founded.  Typo in HFLAGS_PR.  :-)

Heh :).

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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  reply	other threads:[~2021-03-24  1:59 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-15 18:45 [PATCH v4 00/17] target/ppc: Fix truncation of env->hflags Richard Henderson
2021-03-15 18:45 ` [PATCH v4 01/17] target/ppc: Move helper_regs.h functions out-of-line Richard Henderson
2021-03-16  8:12   ` Cédric Le Goater
2021-03-22  3:25   ` David Gibson
2021-03-15 18:46 ` [PATCH v4 02/17] target/ppc: Move 601 hflags adjustment to hreg_compute_hflags Richard Henderson
2021-03-16  8:12   ` Cédric Le Goater
2021-03-22  3:35   ` David Gibson
2021-03-15 18:46 ` [PATCH v4 03/17] target/ppc: Properly sync cpu state with new msr in cpu_load_old Richard Henderson
2021-03-16  8:15   ` Cédric Le Goater
2021-03-22 16:53     ` Richard Henderson
2021-03-22 23:19       ` David Gibson
2021-03-22  3:38   ` David Gibson
2021-03-15 18:46 ` [PATCH v4 04/17] target/ppc: Do not call hreg_compute_mem_idx after ppc_store_msr Richard Henderson
2021-03-16  8:16   ` Cédric Le Goater
2021-03-22  3:39   ` David Gibson
2021-03-15 18:46 ` [PATCH v4 05/17] target/ppc: Retain hflags_nmsr only for migration Richard Henderson
2021-03-16  8:16   ` Cédric Le Goater
2021-03-22  3:41   ` David Gibson
2021-03-15 18:46 ` [PATCH v4 06/17] target/ppc: Fix comment for MSR_FE{0,1} Richard Henderson
2021-03-16  8:16   ` Cédric Le Goater
2021-03-22  3:42   ` David Gibson
2021-03-15 18:46 ` [PATCH v4 07/17] target/ppc: Disconnect hflags from MSR Richard Henderson
2021-03-22  3:52   ` David Gibson
2021-03-22 16:55     ` Richard Henderson
2021-03-22 23:54       ` David Gibson
2021-03-23 17:04         ` Richard Henderson
2021-03-24  1:42           ` David Gibson [this message]
2021-03-15 18:46 ` [PATCH v4 08/17] target/ppc: Reduce env->hflags to uint32_t Richard Henderson
2021-03-16  8:17   ` Cédric Le Goater
2021-03-22  3:53   ` David Gibson
2021-03-15 18:46 ` [PATCH v4 09/17] target/ppc: Put dbcr0 single-step bits into hflags Richard Henderson
2021-03-22  3:55   ` David Gibson
2021-03-15 18:46 ` [PATCH v4 10/17] target/ppc: Create helper_scv Richard Henderson
2021-03-22  4:00   ` David Gibson
2021-03-22 17:05     ` Richard Henderson
2021-03-22 23:55       ` David Gibson
2021-03-15 18:46 ` [PATCH v4 11/17] target/ppc: Put LPCR[GTSE] in hflags Richard Henderson
2021-03-22  4:18   ` David Gibson
2021-03-15 18:46 ` [PATCH v4 12/17] target/ppc: Remove MSR_SA and MSR_AP from hflags Richard Henderson
2021-03-22  4:20   ` David Gibson
2021-03-15 18:46 ` [PATCH v4 13/17] target/ppc: Remove env->immu_idx and env->dmmu_idx Richard Henderson
2021-03-22  4:26   ` David Gibson
2021-03-22 17:27     ` Richard Henderson
2021-03-23  0:01       ` David Gibson
2021-03-15 18:46 ` [PATCH v4 14/17] hw/ppc/pnv_core: Update hflags after setting msr Richard Henderson
2021-03-22  4:27   ` David Gibson
2021-03-15 18:46 ` [PATCH v4 15/17] hw/ppc/spapr_rtas: " Richard Henderson
2021-03-22  4:27   ` David Gibson
2021-03-15 18:46 ` [PATCH v4 16/17] linux-user/ppc: Fix msr updates for signal handling Richard Henderson
2021-03-15 18:46 ` [PATCH v4 17/17] target/ppc: Validate hflags with CONFIG_DEBUG_TCG Richard Henderson
2021-03-16  8:11 ` [PATCH v4 00/17] target/ppc: Fix truncation of env->hflags Cédric Le Goater

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