On 2020-05-26 17:29, James Morse wrote:

Hi Marc,

On 22/04/2020 13:00, Marc Zyngier wrote:

quoted

As ELR-EL1 is a VNCR-capable register with ARMv8.4-NV, let's move it 
to
the sys_regs array and repaint the accessors. While we're at it, let's
kill the now useless accessors used only on the fault injection path.

Reviewed-by: James Morse <james.morse@arm.com>


A curiosity:

quoted

diff --git a/arch/arm64/include/asm/kvm_host.h 

b/arch/arm64/include/asm/kvm_host.h
index 95977b80265ce..46949fce3e813 100644

--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h

@@ -184,6 +184,8 @@ enum vcpu_sysreg {

Comment above the enum has some claims about the order, but its
already out of order with
__vcpu_read_sys_reg_from_cpu()... (PAR_EL1 being the culprit)

This comment dates back from the original assembly implementation,
where I was paranoid about accessing the sys_regs array in strict
order to maximize the chances of the prefetcher doing the right thing.

As always with premature optimization, it was worthless, and moving
things to C forced us to do things differently anyway (not to mention
VHE...).

I'll delete the comment in a separate patch.

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel