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exec.c: Collect AddressSpace related fields into a CPUAddressSpace struct

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Gather up all the fields currently in CPUState which deal with the CPU's
AddressSpace into a separate CPUAddressSpace struct. This paves the way
for allowing the CPU to know about more than one AddressSpace.

The rearrangement also allows us to make the MemoryListener a directly
embedded object in the CPUAddressSpace (it could not be embedded in
CPUState because 'struct MemoryListener' isn't defined for the user-only
builds). This allows us to resolve the FIXME in tcg_commit() by going
directly from the MemoryListener to the CPUAddressSpace.

This patch extracts the actual update of the cached dispatch pointer
from cpu_reload_memory_map() (which is renamed accordingly to
cpu_reloading_memory_map() as it is only responsible for breaking
cpu-exec.c's RCU critical section now). This lets us keep the definition
of the CPUAddressSpace struct private to exec.c.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <1443709790-25180-4-git-send-email-peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Peter Maydell 2015-10-01 15:29:50 +01:00 • committed by Paolo Bonzini
parent 53f8a5e9e2
commit 32857f4d5e
5 changed files with 48 additions and 31 deletions
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13
cpu-exec-common.c
View file

@ -37,10 +37,8 @@ void cpu_resume_from_signal(CPUState *cpu, void *puc)
siglongjmp(cpu->jmp_env, 1);
}
void cpu_reload_memory_map(CPUState *cpu)
void cpu_reloading_memory_map(void)
{
AddressSpaceDispatch *d;
if (qemu_in_vcpu_thread()) {
/* The guest can in theory prolong the RCU critical section as long
* as it feels like. The major problem with this is that because it
@ -59,17 +57,12 @@ void cpu_reload_memory_map(CPUState *cpu)
* part of this callback might become unnecessary.)
*
* This pair matches cpu_exec's rcu_read_lock()/rcu_read_unlock(), which
* only protects cpu->as->dispatch. Since we reload it below, we can
* split the critical section.
* only protects cpu->as->dispatch. Since we know our caller is about
* to reload it, it's safe to split the critical section.
*/
rcu_read_unlock();
rcu_read_lock();
}
/* The CPU and TLB are protected by the iothread lock. */
d = atomic_rcu_read(&cpu->as->dispatch);
cpu->memory_dispatch = d;
tlb_flush(cpu, 1);
}
#endif