This gets rid of shenanigans with relocating the jump table around the
place.
Also clean up bios_info table while we are updating it.
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
To make memory management easier in hvmloader, defer building a
generic E820 map until the end of hvmloader bootstrap.
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
When creating an HVM domain, if e.g. another domain is created before
qemu allocates video memory, the extra 8MB memory ballooning is not
available any more, because it got consumed by the other domain.
This fixes it by taking video memory from the main memory:
- make hvmloader use e820_malloc to reserve some of the main memory
and notify ioemu of its address through the Xen platform PCI card.
- add XENMAPSPACE_mfn to the xen_add_to_physmap memory op, to allow
ioemu to move the MFNs between the original position and the PCI
mapping, when LFB acceleration is disabled/enabled
- add a remove_from_physmap memory op, to allow ioemu to unmap it
completely for the case of old guests with acceleration disabled.
- add xc_domain_memory_translate_gpfn_list to libxc to allow ioemu to
get the MFNs of the video memory.
- have xend save the PCI memory space instead of ioemu: if a memory
page is there, the guest can access it like usual memory, so xend
can safely be responsible to save it. The extra benefit is that
live migration will apply the logdirty optimization there too.
- handle old saved images, populating the video memory from ioemu if
really needed.
Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>
compiled with gcc and linked into the hvmloader as a byte-array.
Hvmloader allocates memory (rounded up to next 64kb) from the e820
table
below 4GB, copies and relocates the 32bit code in the allocated area
and
copies a jumptable (located in a section '.biosjumptable') pointing to
the 'exported' functions into the Bochs BIOS's memory area to link the
two code sections. The memory area has been reserved and can be
identified with the signature '___JMPT'.
In the Bochs BIOS only stub functions are provided. These load the
index
of a particular function in the jump table, switch to protected mode
and
call the function in the high memory area. The stack is prepared such
that functions compiled by gcc can just pick the parameters from the
stack as usual - this means that the 16bit real-mode return address is
taken off the stack. The stub functions should have the same signature
as those in 32bit space. For ABI compatibility reasons parameters
inside
the Bochs BIOS stubs should all be 32bit wide.
This patch includes a test function that calls three gcc-compiled
functions in the high memory area and displays their success status.
Simple tests are done doing multiplication and addition of 32-bit
numbers and reading and modification of a static variable. These
functions test the interface and the relocation code. The test code is
removed in patch part 3.
Signed-off-by: Stefan Berger <stefanb@us.ibm.com>
Keir Fraser
Keir Fraser
kfraser@localhost.localdomain
kaf24@localhost.localdomain