Commit a43fb7da authored by Maran Wilson's avatar Maran Wilson Committed by Boris Ostrovsky
Browse files

xen/pvh: Move Xen code for getting mem map via hcall out of common file 



We need to refactor PVH entry code so that support for other hypervisors
like Qemu/KVM can be added more easily.

The original design for PVH entry in Xen guests relies on being able to
obtain the memory map from the hypervisor using a hypercall. When we
extend the PVH entry ABI to support other hypervisors like Qemu/KVM,
a new mechanism will be added that allows the guest to get the memory
map without needing to use hypercalls.

For Xen guests, the hypercall approach will still be supported. In
preparation for adding support for other hypervisors, we can move the
code that uses hypercalls into the Xen specific file. This will allow us
to compile kernels in the future without CONFIG_XEN that are still capable
of being booted as a Qemu/KVM guest via the PVH entry point.

Signed-off-by: default avatarMaran Wilson <maran.wilson@oracle.com>
Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
parent 8cee3974

arch/x86/platform/pvh/enlighten.c

+14 −15
Original line number Diff line number Diff line
@@ -8,11 +8,7 @@ 
#include <asm/e820/api.h>

#include <asm/x86_init.h>



#include <asm/xen/interface.h>

#include <asm/xen/hypercall.h>



#include <xen/xen.h>

#include <xen/interface/memory.h>

#include <xen/interface/hvm/start_info.h>



/*
@@ -31,21 +27,24 @@ static u64 pvh_get_root_pointer(void) 
	return pvh_start_info.rsdp_paddr;

}



static void __init init_pvh_bootparams(void)

/*

 * Xen guests are able to obtain the memory map from the hypervisor via the

 * HYPERVISOR_memory_op hypercall.

 * If we are trying to boot a Xen PVH guest, it is expected that the kernel

 * will have been configured to provide an override for this routine to do

 * just that.

 */

void __init __weak mem_map_via_hcall(struct boot_params *ptr __maybe_unused)

{

	struct xen_memory_map memmap;

	int rc;

	xen_raw_printk("Error: Could not find memory map\n");

	BUG();

}



static void __init init_pvh_bootparams(void)

{

	memset(&pvh_bootparams, 0, sizeof(pvh_bootparams));



	memmap.nr_entries = ARRAY_SIZE(pvh_bootparams.e820_table);

	set_xen_guest_handle(memmap.buffer, pvh_bootparams.e820_table);

	rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);

	if (rc) {

		xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc);

		BUG();

	}

	pvh_bootparams.e820_entries = memmap.nr_entries;

	mem_map_via_hcall(&pvh_bootparams);



	if (pvh_bootparams.e820_entries < E820_MAX_ENTRIES_ZEROPAGE - 1) {

		pvh_bootparams.e820_table[pvh_bootparams.e820_entries].addr =

arch/x86/xen/enlighten_pvh.c

+20 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#include <linux/acpi.h>



#include <xen/hvc-console.h>



#include <asm/io_apic.h>

#include <asm/hypervisor.h>

#include <asm/e820/api.h>



#include <xen/xen.h>

#include <asm/xen/interface.h>

#include <asm/xen/hypercall.h>



#include <xen/interface/memory.h>



/*

 * PVH variables.

 *
@@ -28,3 +33,18 @@ void __init xen_pvh_init(void) 
	pfn = __pa(hypercall_page);

	wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));

}



void __init mem_map_via_hcall(struct boot_params *boot_params_p)

{

	struct xen_memory_map memmap;

	int rc;



	memmap.nr_entries = ARRAY_SIZE(boot_params_p->e820_table);

	set_xen_guest_handle(memmap.buffer, boot_params_p->e820_table);

	rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);

	if (rc) {

		xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc);

		BUG();

	}

	boot_params_p->e820_entries = memmap.nr_entries;

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE