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target/arm: Correct calculation of tlb range invalidate length 

The calculation of the length of TLB range invalidate operations
in tlbi_aa64_range_get_length() is incorrect in two ways:
 * the NUM field is 5 bits, but we read only 4 bits
 * we miscalculate the page_shift value, because of an
   off-by-one error:
    TG 0b00 is invalid
    TG 0b01 is 4K granule size == 4096 == 2^12
    TG 0b10 is 16K granule size == 16384 == 2^14
    TG 0b11 is 64K granule size == 65536 == 2^16
   so page_shift should be (TG - 1) * 2 + 12

Thanks to the bug report submitter Cha HyunSoo for identifying
both these errors.

Fixes: 84940ed825 ("target/arm: Add support for FEAT_TLBIRANGE")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/734
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20211130173257.1274194-1-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2021-11-30 17:32:57 +00:00
parent 3508c0fac2
commit 52a9f60935
1 changed files with 3 additions and 3 deletions
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6
target/arm/helper.c
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@ -4519,18 +4519,18 @@ static uint64_t tlbi_aa64_range_get_length(CPUARMState *env,
uint64_t exponent;
uint64_t length;
num = extract64(value, 39, 4);
num = extract64(value, 39, 5);
scale = extract64(value, 44, 2);
page_size_granule = extract64(value, 46, 2);
page_shift = page_size_granule * 2 + 12;
if (page_size_granule == 0) {
qemu_log_mask(LOG_GUEST_ERROR, "Invalid page size granule %d\n",
page_size_granule);
return 0;
}
page_shift = (page_size_granule - 1) * 2 + 12;
exponent = (5 * scale) + 1;
length = (num + 1) << (exponent + page_shift);