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Gabriel Krisman Bertazi authored
When reading the i915_energy_uJ debugfs file, it tries to fetch MSR_RAPL_POWER_UNIT, which might not be available, like in a vm environment, causing the exception shown below. We can easily prevent it by doing a rdmsrl_safe read instead, which will handle the exception, allowing us to abort the debugfs file read. This was caught by the new igt@debugfs_test@read_all_entries testcase in the CI. unchecked MSR access error: RDMSR from 0x606 at rIP:0xffffffffa0078f66 (i915_energy_uJ+0x36/0xb0 [i915]) Call Trace: seq_read+0xdc/0x3a0 full_proxy_read+0x4f/0x70 __vfs_read+0x23/0x120 ? putname+0x4f/0x60 ? rcu_read_lock_sched_held+0x75/0x80 ? entry_SYSCALL_64_fastpath+0x5/0xb1 vfs_read+0xa0/0x150 SyS_read+0x44/0xb0 entry_SYSCALL_64_fastpath+0x1c/0xb1 RIP: 0033:0x7f1f5e9f4500 RSP: 002b:00007ffc77e65cf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: ffffffff8146e003 RCX: 00007f1f5e9f4500 RDX: 0000000000000200 RSI: 00007ffc77e65d10 RDI: 0000000000000006 RBP: ffffc900007abf88 R08: 0000000001eaff20 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000006 R14: 0000000000000005 R15: 0000000001eb94db ? __this_cpu_preempt_check+0x13/0x20 v2: - Drop unsigned long long cast and improve calculation (Chris) Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101901Signed-off-by:
Gabriel Krisman Bertazi <krisman@collabora.co.uk> Link: https://patchwork.freedesktop.org/patch/msgid/87o9s7zrx3.fsf@dilma.collabora.co.ukReviewed-by:
Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by:
Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by:
Daniel Vetter <daniel.vetter@ffwll.ch>
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