genode/repos/ports/include/vmm/guest_memory.h
Norman Feske 17c79a9e23 base: avoid use of deprecated base/printf.h
Besides adapting the components to the use of base/log.h, the patch
cleans up a few base headers, i.e., it removes unused includes from
root/component.h, specifically base/heap.h and
ram_session/ram_session.h. Hence, components that relied on the implicit
inclusion of those headers have to manually include those headers now.

While adjusting the log messages, I repeatedly stumbled over the problem
that printing char * arguments is ambiguous. It is unclear whether to
print the argument as pointer or null-terminated string. To overcome
this problem, the patch introduces a new type 'Cstring' that allows the
caller to express that the argument should be handled as null-terminated
string. As a nice side effect, with this type in place, the optional len
argument of the 'String' class could be removed. Instead of supplying a
pair of (char const *, size_t), the constructor accepts a 'Cstring'.
This, in turn, clears the way let the 'String' constructor use the new
output mechanism to assemble a string from multiple arguments (and
thereby getting rid of snprintf within Genode in the near future).

To enforce the explicit resolution of the char * ambiguity, the 'char *'
overload of the 'print' function is marked as deleted.

Issue #1987
2016-08-29 17:27:10 +02:00

97 lines
2.6 KiB
C++

/*
* \brief Utilities for implementing VMMs on Genode/NOVA
* \author Norman Feske
* \date 2013-08-20
*
* The VMM and the guest share the same PD. However, the guest's view on the PD
* is restricted to the guest-physical-to-VMM-local mappings installed by the
* VMM for the VCPU's EC.
*
* The guest memory is shadowed at the lower portion of the VMM's address
* space. If the guest (the VCPU EC) tries to access a page that has no mapping
* in the VMM's PD, NOVA does not generate a page-fault (which would be
* delivered to the pager of the VMM, i.e., core) but it produces a NPT
* virtualization event handled locally by the VMM. The NPT event handler is
* the '_svm_npt' function.
*/
/*
* Copyright (C) 2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _INCLUDE__VMM__GUEST_MEMORY_H_
#define _INCLUDE__VMM__GUEST_MEMORY_H_
/* Genode includes */
#include <os/attached_ram_dataspace.h>
#include <rm_session/connection.h>
#include <region_map/client.h>
/* VMM utilities includes */
#include <vmm/types.h>
namespace Vmm {
using namespace Genode;
class Virtual_reservation;
class Guest_memory;
}
/**
* The 'Virtual_reservation' is a managed dataspace that occupies the lower
* part of the address space, which contains the shadow of the VCPU's physical
* memory.
*/
struct Vmm::Virtual_reservation : private Rm_connection, Region_map_client
{
Virtual_reservation(addr_t vm_size)
:
Region_map_client(Rm_connection::create(vm_size))
{
try {
/*
* Attach reservation to the beginning of the local address
* space. We leave out the very first page because core denies
* the attachment of anything at the zero page.
*/
env()->rm_session()->attach_at(Region_map_client::dataspace(),
PAGE_SIZE, 0, PAGE_SIZE);
} catch (Rm_session::Region_conflict) {
error("region conflict while attaching guest-physical memory");
}
}
~Virtual_reservation()
{
env()->rm_session()->detach((void *)PAGE_SIZE);
}
};
/**
* Representation of guest memory
*
*/
struct Vmm::Guest_memory : Attached_ram_dataspace
{
/**
* Constructor
*
* \param backing_store_size number of bytes of physical RAM to be
* used as guest-physical and device memory,
* allocated from core's RAM service
*/
Guest_memory(size_t backing_store_size)
:
Attached_ram_dataspace(env()->ram_session(), backing_store_size)
{ }
};
#endif /* _INCLUDE__VMM__GUEST_MEMORY_H_ */