Re: [PATCH v2 3/6] KVM: arm64: Support pvlock preempted via shared structure

From
Steven Price <steven.price@arm.com>
Date
2020-01-13 10:31:27
Also in
kvm, kvmarm, linux-arm-kernel, linux-doc, lkml
Reply to
yezengruan, 2020-01-11
On Sat, Jan 11, 2020 at 07:30:42AM +0000, yezengruan wrote:
Hi Steve,

On 2020/1/9 23:02, Steven Price wrote:
quoted
On 26/12/2019 13:58, Zengruan Ye wrote:
quoted
Implement the service call for configuring a shared structure between a
VCPU and the hypervisor in which the hypervisor can tell the VCPU is
running or not.

The preempted field is zero if 1) some old KVM deos not support this filed.
NIT: s/deos/does/
Thanks for posting this.
quoted
However, I would hope that the service call will fail if it's an old KVM not simply return zero.
Sorry, I'm not sure what you mean. The service call will fail if it's an old KVM, and the Guest will use __native_vcpu_is_preempted.
You previously said the "field is zero if [...] some old KVM does not
support this field". This seems a bit of an odd statement, because the
field just doesn't exist (it's an old KVM so won't have allocated it),
and if the guest attempts to find the field using the service call then
the call will fail.

So I'm not sure in what situation you are expecting the field to be zero
on an old KVM.

Steve
Thread (2 messages) 2 messages, 2 authors, last reply 2020-01-13
Keyboard shortcuts
hback out one level
jnext message in thread / next series-diff position
kprevious message in thread / previous series-diff position
ldrill in
Escclose help / fold thread tree
?toggle this help