diff options
Diffstat (limited to 'gitlab/issues_text/target_arm/host_missing/accel_missing/2226')
| -rw-r--r-- | gitlab/issues_text/target_arm/host_missing/accel_missing/2226 | 56 |
1 files changed, 0 insertions, 56 deletions
diff --git a/gitlab/issues_text/target_arm/host_missing/accel_missing/2226 b/gitlab/issues_text/target_arm/host_missing/accel_missing/2226 deleted file mode 100644 index 59c8bcc69..000000000 --- a/gitlab/issues_text/target_arm/host_missing/accel_missing/2226 +++ /dev/null @@ -1,56 +0,0 @@ -arm HSTR trap settings routed to EL1 instead of EL2 -Description of problem: -ARM's HSTR register is used to trap CP15 access from EL1/0. qemu's implementation seems to be inconsistent with ARM's documentation. - -Take the system register VBAR for example, the following pseudo code is grabbed from ARM DDI 0487J.a ID042523 G8-10651, which is the logics behind when reading VBAR. -``` -if PSTATE.EL == EL0 then - UNDEFINED; -elsif PSTATE.EL == EL1 then - if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T12 == '1' then - AArch64.AArch32SystemAccessTrap(EL2, 0x03); - elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T12 == '1' then - AArch32.TakeHypTrapException(0x03); - elsif HaveEL(EL3) && ELUsingAArch32(EL3) then - R[t] = VBAR_NS; - else - R[t] = VBAR; -elsif PSTATE.EL == EL2 then - if HaveEL(EL3) && ELUsingAArch32(EL3) then - R[t] = VBAR_NS; - else - R[t] = VBAR; -elsif PSTATE.EL == EL3 then - if SCR.NS == '0' then - R[t] = VBAR_S; - else - R[t] = VBAR_NS; -``` - -The main logics in my attached test program are: -1. Setting EL2 and EL1's exception table -2. Set HSTR.T12 -3. ERET to EL1, and read VBAR from EL1 - -As the document mentions, when CPU running on EL1 && HSTR.T12 is set, HypTrapException 0x3 should be taken, which is EL2. But the test program shows, on such circumstances, CPU is being routed to EL1's undefined exception. -Steps to reproduce: -1. Clone this repo https://github.com/roolrz/reproduce-qemu-arm-hstr-issue -2. Use make to build the test program -3. Use following command to launch it -``` -qemu-system-arm \ - -nographic \ - -cpu cortex-a7 \ - -M virt,virtualization=on \ - -m 1G \ - -kernel el2.elf -``` -4. The following message is printed by the program, problem reproduced -``` -EL2 Booted -Jumping to el1 -el1 reached, triggering trap -EL1 undefined sync triggered -``` -Additional information: - |