On 05/09/2013 03:33 PM, Bhushan Bharat-R65777 wrote:
-----Original Message-----
From: Linuxppc-dev [mailto:linuxppc-dev-
bounces+bharat.bhushan=freescale.com@xxxxxxxxxxxxxxxx] On Behalf Of Caraman
Mihai Claudiu-B02008
Sent: Wednesday, May 08, 2013 6:44 PM
To: Wood Scott-B07421; tiejun.chen
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx; agraf@xxxxxxx; kvm-ppc@xxxxxxxxxxxxxxx;
kvm@xxxxxxxxxxxxxxx
Subject: RE: [RFC][KVM][PATCH 1/1] kvm:ppc:booke-64: soft-disable interrupts
This only disable soft interrupt for kvmppc_restart_interrupt() that
restarts interrupts if they were meant for the host:
a. SOFT_DISABLE_INTS() only for BOOKE_INTERRUPT_EXTERNAL |
BOOKE_INTERRUPT_DECREMENTER | BOOKE_INTERRUPT_DOORBELL
Those aren't the only exceptions that can end up going to the host.
We could get a TLB miss that results in a heavyweight MMIO exit, etc.
And shouldn't we handle kvmppc_restart_interrupt() like the original
HOST flow?
#define MASKABLE_EXCEPTION(trapnum, intnum, label, hdlr,
ack) \
START_EXCEPTION(label); \
NORMAL_EXCEPTION_PROLOG(trapnum, intnum,
PROLOG_ADDITION_MASKABLE)\
EXCEPTION_COMMON(trapnum, PACA_EXGEN,
*INTS_DISABLE*) \
...
Could you elaborate on what you mean?
I think Tiejun was saying that host has flags and replays only EE/DEC/DBELL
interrupts. There is special macro masked_interrupt_book3e in those exception
handlers that sets paca->irq_happened.
The list of replied interrupts is limited to asynchronous noncritical interrupts
which can be masked by MSR[EE] (therefore no TLB miss).
Embedded Perfmon interrupt is also asynchronous, Why that is not in the list of masked interruts.
Are you saying perfmon? If so, its also in that list:
START_EXCEPTION(perfmon);
NORMAL_EXCEPTION_PROLOG(0x260, BOOKE_INTERRUPT_PERFORMANCE_MONITOR,
PROLOG_ADDITION_NONE)
EXCEPTION_COMMON(0x260, PACA_EXGEN, INTS_DISABLE)
Tiejun
-Bharat
Now on KVM book3e we
don't want to put them in the irq_happened lazy state but rather to execute them
directly, so there is no reason for exception handling symmetry between host and
guest.
-Mike
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