Re: [PATCH] Add ability to drop pages through testdev

Avi Kivity
2010-12-29T09:58:35Z

On 12/29/2010 11:55 AM, Gleb Natapov wrote:
> On Wed, Dec 29, 2010 at 11:50:48AM +0200, Avi Kivity wrote:
> > On 12/22/2010 05:18 PM, Gleb Natapov wrote:
> > >Signed-off-by: Gleb Natapov<gleb@redhat.com>
> > >diff --git a/hw/testdev.c b/hw/testdev.c
> > >index d1abf59..29df385 100644
> > >--- a/hw/testdev.c
> > >+++ b/hw/testdev.c
> > >@@ -1,3 +1,4 @@
> > >+#include<sys/mman.h>
> > > #include "hw.h"
> > > #include "qdev.h"
> > > #include "isa.h"
> > >@@ -46,6 +47,16 @@ static uint32_t test_device_ioport_read(void *opaque, uint32_t addr)
> > > return test_device_ioport_data;
> > > }
> > >
> > >+static void test_device_flush_page(void *opaque, uint32_t addr, uint32_t data)
> > >+{
> > >+ target_phys_addr_t len = 4096;
> > >+ void *a = cpu_physical_memory_map(data& ~0xffful,&len, 0);
> > >+
> > >+ mprotect(a, 4096, PROT_NONE);
> > >+ mprotect(a, 4096, PROT_READ|PROT_WRITE);
> > >+ cpu_physical_memory_unmap(a, len, 0, 0);
> > >+}
> > >+
> >
> > Icky. This is much better done through the api tests. Applied it
> > so as not to spoil all the effort.
> >
> How would you do that there?

Set up all the state using the KVM_SET_REGS family, pointing to the
instruction you want to test, and KVM_RUN that. You can even queue
exceptions and interrupts for complicated cases.