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Diffstat (limited to 'gitlab/issues/target_arm/host_missing/accel_TCG/734.toml')
| -rw-r--r-- | gitlab/issues/target_arm/host_missing/accel_TCG/734.toml | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/gitlab/issues/target_arm/host_missing/accel_TCG/734.toml b/gitlab/issues/target_arm/host_missing/accel_TCG/734.toml new file mode 100644 index 00000000..7845a826 --- /dev/null +++ b/gitlab/issues/target_arm/host_missing/accel_TCG/734.toml @@ -0,0 +1,36 @@ +id = 734 +title = "aarch64 tlb range invalidate is not accurate" +state = "closed" +created_at = "2021-11-18T07:58:24.759Z" +closed_at = "2021-12-15T20:11:57.280Z" +labels = ["accel: TCG", "target: arm"] +url = "https://gitlab.com/qemu-project/qemu/-/issues/734" +host-os = "Ubuntu 20.04" +host-arch = "x86_64" +qemu-version = "6.1.9.0 (v6.2.0-rc0)" +guest-os = "N/A" +guest-arch = "aarch64" +description = """In this (https://gitlab.com/qemu-project/qemu/-/commit/84940ed82552d3c7c7327c83076b02cee7978257) commit, tlb range invalidate support is added, and I think qemu's range calculation is wrong. + +In `tlbi_aa64_range_get_length` function, `num`, `scale`, `page_size_granule` is caculated as below. + + +``` + num = extract64(value, 39, 4); + scale = extract64(value, 44, 2); + page_size_granule = extract64(value, 46, 2); + + page_shift = page_size_granule * 2 + 12; +``` + +As [Arm documentation](https://developer.arm.com/documentation/ddi0595/2021-06/AArch64-Instructions/TLBI-RVALE1--TLBI-RVALE1NXS--TLB-Range-Invalidate-by-VA--Last-level--EL1), NUM bits's length is 5, but the code above only extract 4bits. + +And `page_shift` also should be calculated as `(page_size_granule-1) <<1) + 12` rather than `page_size_granule * 2 + 12`.""" +reproduce = """1. +2. +3.""" +additional = """I found this issue while debugging a phenomenon that kernel panic occurs randomly in my qemu fork. + +I'm pretty sure this is one of the causes, but even if I roughly correct it, my problem has not been solved. + +I think my problem is TLB invalidate related issue, so if I find any more problems, I'll comment here.""" |