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accel/tcg: Use TLB_FORCE_SLOW not TLB_MMIO for user-only plugins

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In 6d03226b42 we set TLB_MMIO to a non-zero value for user-only
so that we could return a non-zero value from probe_* functions
so that we could force callers like Arm SVE vector moves to use
the slow path rather than direct access.  All for the sake of
exposing these accesses to plugins.

Back then, TLB_FORCE_SLOW did not exist, so TLB_MMIO seemed like
a reasonable solution.  However, user-only doesn't really have
MMIO and this has knock-on effects, like forcing Arm SVE first-fault
vector loads to stop.  Better to use TLB_FORCE_SLOW as a more exact
trigger for plugins.

Cc: qemu-stable@nongnu.org
Fixes: 6d03226b42 ("plugins: force slow path when plugins instrument memory ops")
Acked-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20260702171057.47998-1-richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson
2026-07-02 10:10:56 -07:00
parent 94826ec137
commit b79a9b6e5b
2 changed files with 6 additions and 5 deletions
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7
include/exec/tlb-flags.h
View File

@@ -27,12 +27,13 @@
/*
* Allow some level of source compatibility with softmmu.
* Invalid is set when the page does not have requested permissions.
* MMIO is set when we want the target helper to use the functional
* INVALID is set when the page does not have requested permissions.
* FORCE_SLOW is set when we want the target helper to use the functional
* interface for load/store so that plugins see the access.
*/
#define TLB_INVALID_MASK (1 << 0)
#define TLB_MMIO (1 << 1)
#define TLB_FORCE_SLOW (1 << 1)
#define TLB_MMIO 0
#define TLB_WATCHPOINT 0
#else