From: Richard Henderson <richard.henderson@linaro.org>
To: Nicholas Piggin <npiggin@gmail.com>,
qemu-devel@nongnu.org, qemu-ppc@nongnu.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [RFC PATCH] accel/tcg: clear all TBs from a page when it is written to
Date: Wed, 21 Aug 2024 09:16:10 +1000 [thread overview]
Message-ID: <0edf7ee6-9dfe-41a3-a7ae-2f781e855b12@linaro.org> (raw)
In-Reply-To: <D3FESSMCNW22.3S68NMF7NI5KR@gmail.com>
On 8/14/24 16:09, Nicholas Piggin wrote:
>>> @@ -1107,6 +1107,9 @@ tb_invalidate_phys_page_range__locked(struct page_collection *pages,
>>> TranslationBlock *current_tb = retaddr ? tcg_tb_lookup(retaddr) : NULL;
>>> #endif /* TARGET_HAS_PRECISE_SMC */
>>>
>>> + start &= TARGET_PAGE_MASK;
>>> + last |= ~TARGET_PAGE_MASK;
>>> +
>>> /* Range may not cross a page. */
>>> tcg_debug_assert(((start ^ last) & TARGET_PAGE_MASK) == 0);
>>
>> This would definitely break SMC.
>
> They can't invalidate the instruction currently being executed?
They can. But that's where adjusting start/last would break things, because we've lost
track of exactly what's being modified, which changes the result of "did we modify the
current instruction".
r~
prev parent reply other threads:[~2024-08-20 23:16 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-09 7:47 [RFC PATCH] accel/tcg: clear all TBs from a page when it is written to Nicholas Piggin
2024-08-09 8:26 ` Philippe Mathieu-Daudé
2024-08-12 1:25 ` Richard Henderson
2024-08-14 6:09 ` Nicholas Piggin
2024-08-20 23:16 ` Richard Henderson [this message]
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