diff options
| author | julia <midnight@trainwit.ch> | 2025-02-03 17:18:52 +1100 |
|---|---|---|
| committer | Alistair Francis <alistair.francis@wdc.com> | 2025-03-04 15:42:54 +1000 |
| commit | 50df464f8e9ddcc5242c058728e12c299c59db02 (patch) | |
| tree | 4e5f05317fb148b8c234a3c12b2b60c7404c3145 | |
| parent | bda6522e3f9002040fc223c12457b849328a1d39 (diff) | |
| download | qemu-50df464f8e9ddcc5242c058728e12c299c59db02.zip qemu-50df464f8e9ddcc5242c058728e12c299c59db02.tar.gz qemu-50df464f8e9ddcc5242c058728e12c299c59db02.tar.bz2 | |
target/riscv: log guest errors when reserved bits are set in PTEs
For instance, QEMUs newer than b6ecc63c569bb88c0fcadf79fb92bf4b88aefea8
would silently treat this akin to an unmapped page (as required by the
RISC-V spec, admittedly). However, not all hardware platforms do (e.g.
CVA6) which leads to an apparent QEMU bug.
Instead, log a guest error so that in future, incorrectly set up page
tables can be debugged without bisecting QEMU.
Signed-off-by: julia <midnight@trainwit.ch>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20250203061852.2931556-1-midnight@trainwit.ch>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
| -rw-r--r-- | target/riscv/cpu_helper.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c index 356e84b..3f5fd86 100644 --- a/target/riscv/cpu_helper.c +++ b/target/riscv/cpu_helper.c @@ -1472,14 +1472,27 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical, ppn = pte >> PTE_PPN_SHIFT; } else { if (pte & PTE_RESERVED) { + qemu_log_mask(LOG_GUEST_ERROR, "%s: reserved bits set in PTE: " + "addr: 0x%" HWADDR_PRIx " pte: 0x" TARGET_FMT_lx "\n", + __func__, pte_addr, pte); return TRANSLATE_FAIL; } if (!pbmte && (pte & PTE_PBMT)) { + /* Reserved without Svpbmt. */ + qemu_log_mask(LOG_GUEST_ERROR, "%s: PBMT bits set in PTE, " + "and Svpbmt extension is disabled: " + "addr: 0x%" HWADDR_PRIx " pte: 0x" TARGET_FMT_lx "\n", + __func__, pte_addr, pte); return TRANSLATE_FAIL; } if (!riscv_cpu_cfg(env)->ext_svnapot && (pte & PTE_N)) { + /* Reserved without Svnapot extension */ + qemu_log_mask(LOG_GUEST_ERROR, "%s: N bit set in PTE, " + "and Svnapot extension is disabled: " + "addr: 0x%" HWADDR_PRIx " pte: 0x" TARGET_FMT_lx "\n", + __func__, pte_addr, pte); return TRANSLATE_FAIL; } @@ -1490,14 +1503,19 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical, /* Invalid PTE */ return TRANSLATE_FAIL; } + if (pte & (PTE_R | PTE_W | PTE_X)) { goto leaf; } - /* Inner PTE, continue walking */ if (pte & (PTE_D | PTE_A | PTE_U | PTE_ATTR)) { + /* D, A, and U bits are reserved in non-leaf/inner PTEs */ + qemu_log_mask(LOG_GUEST_ERROR, "%s: D, A, or U bits set in non-leaf PTE: " + "addr: 0x%" HWADDR_PRIx " pte: 0x" TARGET_FMT_lx "\n", + __func__, pte_addr, pte); return TRANSLATE_FAIL; } + /* Inner PTE, continue walking */ base = ppn << PGSHIFT; } @@ -1507,10 +1525,17 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical, leaf: if (ppn & ((1ULL << ptshift) - 1)) { /* Misaligned PPN */ + qemu_log_mask(LOG_GUEST_ERROR, "%s: PPN bits in PTE is misaligned: " + "addr: 0x%" HWADDR_PRIx " pte: 0x" TARGET_FMT_lx "\n", + __func__, pte_addr, pte); return TRANSLATE_FAIL; } if (!pbmte && (pte & PTE_PBMT)) { /* Reserved without Svpbmt. */ + qemu_log_mask(LOG_GUEST_ERROR, "%s: PBMT bits set in PTE, " + "and Svpbmt extension is disabled: " + "addr: 0x%" HWADDR_PRIx " pte: 0x" TARGET_FMT_lx "\n", + __func__, pte_addr, pte); return TRANSLATE_FAIL; } |