From: Richard Henderson <rth@twiddle.net>
To: Peter Maydell <peter.maydell@linaro.org>, qemu-devel@nongnu.org
Cc: qemu-stable@nongnu.org, Paolo Bonzini <pbonzini@redhat.com>,
Stuart Monteith <stuart.monteith@linaro.org>
Subject: Re: [Qemu-devel] [PATCH for-2.11 2/2] accel/tcg: Handle atomic accesses to notdirty memory correctly
Date: Mon, 20 Nov 2017 15:27:44 +0100 [thread overview]
Message-ID: <1aaf0a6f-c38b-d80d-b09a-1a54545c7660@twiddle.net> (raw)
In-Reply-To: <1511184421-23535-3-git-send-email-peter.maydell@linaro.org>
On 11/20/2017 02:27 PM, Peter Maydell wrote:
> - return (void *)((uintptr_t)addr + tlbe->addend);
> + hostaddr = (void *)((uintptr_t)addr + tlbe->addend);
> +
> + memory_notdirty_write_prepare(ndi, ENV_GET_CPU(env), addr,
> + qemu_ram_addr_from_host_nofail(hostaddr),
> + 1 << s_bits);
These calls should be conditional on TLB_NOTDIRTY being set.
We certainly don't need to do anything like taking a lock otherwise.
Perhaps an extra bool in NDI, like
ndi->active = false;
if (unlikely(tlb_addr & TLB_NOTDIRTY)) {
ndi->active = true;
memory_notdirty_write_prepare(ndi, ...);
}
and
#define ATOMIC_MMU_CLEANUP \
do { \
if (unlikely(ndi->active)) { \
memory_notdirty_write_complete(ndi); \
} \
} while (0)
r~
next prev parent reply other threads:[~2017-11-20 14:28 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-20 13:26 [Qemu-devel] [PATCH for-2.11 0/2] Fix TCG atomic writes to nondirty pages Peter Maydell
2017-11-20 13:27 ` [Qemu-devel] [PATCH for-2.11 1/2] exec.c: Factor out before/after actions for notdirty memory writes Peter Maydell
2017-11-20 14:28 ` Richard Henderson
2017-11-20 13:27 ` [Qemu-devel] [PATCH for-2.11 2/2] accel/tcg: Handle atomic accesses to notdirty memory correctly Peter Maydell
2017-11-20 14:27 ` Richard Henderson [this message]
2017-11-20 14:47 ` Peter Maydell
2017-11-20 15:00 ` Richard Henderson
2017-11-20 18:09 ` Peter Maydell
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