From 52a9f60935d394953dd6b47d01bb7eb47bc2592f Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 30 Nov 2021 17:32:57 +0000 Subject: [PATCH] target/arm: Correct calculation of tlb range invalidate length MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: 84940ed82552d3c ("target/arm: Add support for FEAT_TLBIRANGE") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/734 Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Reviewed-by: Alex Bennée Reviewed-by: Philippe Mathieu-Daudé Message-id: 20211130173257.1274194-1-peter.maydell@linaro.org --- target/arm/helper.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index 9b317899a6..db837d53bd 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -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);