Messages in this thread | | | From | Peter Maydell <> | Date | Thu, 7 Jan 2016 17:19:59 +0000 | Subject | Re: [Qemu-devel] arm64 qemu tests failing in linux-next since 'arm64: kernel: enforce pmuserenr_el0 initialization and restore' |
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On 7 January 2016 at 17:10, Guenter Roeck <linux@roeck-us.net> wrote: > Strictly speaking you may be right (regression is a bit strong, though), > but for my part I tend to be pragmatic. > > A warning message such as "Access to unimplemented register X" may be > useful
You can get these from QEMU if you pass it "-d unimp", which logs various kinds of things-not-yet-implemented, with a couple of caveats: * the warning is when we translate the code, not when we execute it * it won't warn for registers which we implement but not completely (eg only partial functionality or dummy reads-as-written)
In this case it printed "write access to unsupported AArch64 system register op0:3 op1:3 crn:9 crm:14 op2:0"
The 'guest_errors' suboption to -d warns about things which appear to be errors in the guest OS, for instance some kinds of UNPREDICTABLE, and may also be of interest.
Neither guest_errors nor unimp are comprehensive (there are many more situations where we don't warn than where we do) but they can be helpful sometimes.
thanks -- PMM
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