KVM: PPC: Book3S HV: Handle virtual mode in XIVE VCPU push code

Browse source

The code in book3s_hv_rmhandlers.S that pushes the XIVE virtual CPU
context to the hardware currently assumes it is being called in real
mode, which is usually true.  There is however a path by which it can
be executed in virtual mode, in the case where indep_threads_mode = N.
A virtual CPU executing on an offline secondary thread can take a
hypervisor interrupt in virtual mode and return from the
kvmppc_hv_entry() call after the kvm_secondary_got_guest label.
It is possible for it to be given another vcpu to execute before it
gets to execute the stop instruction.  In that case it will call
kvmppc_hv_entry() for the second VCPU in virtual mode, and the XIVE
vCPU push code will be executed in virtual mode.  The result in that
case will be a host crash due to an unexpected data storage interrupt
caused by executing the stdcix instruction in virtual mode.

This fixes it by adding a code path for virtual mode, which uses the
virtual TIMA pointer and normal load/store instructions.

[paulus@ozlabs.org - wrote patch description]

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

...

This commit is contained in:

Suraj Jitindar Singh 2019-04-29 18:57:45 +10:00 • committed by Paul Mackerras

parent 1f80ba3d20

commit 7ae9bda7ed

1 changed files with 25 additions and 11 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

36

arch/powerpc/kvm/book3s_hv_rmhandlers.S

View file