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Commit 96f28bc6 authored by David Vrabel's avatar David Vrabel Committed by Konrad Rzeszutek Wilk
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x86/xen: populate boot_params with EDD data 



During early setup of a dom0 kernel, populate boot_params with the
Enhanced Disk Drive (EDD) and MBR signature data.  This makes
information on the BIOS boot device available in /sys/firmware/edd/.

Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
Acked-by: default avatarJan Beulich <jbeulich@suse.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 31880c37

arch/x86/xen/enlighten.c

+52 −0
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ 
#include <linux/pci.h>

#include <linux/gfp.h>

#include <linux/memblock.h>

#include <linux/edd.h>



#include <xen/xen.h>

#include <xen/events.h>
@@ -1306,6 +1307,55 @@ static const struct machine_ops xen_machine_ops __initconst = { 
	.emergency_restart = xen_emergency_restart,

};



static void __init xen_boot_params_init_edd(void)

{

#if IS_ENABLED(CONFIG_EDD)

	struct xen_platform_op op;

	struct edd_info *edd_info;

	u32 *mbr_signature;

	unsigned nr;

	int ret;



	edd_info = boot_params.eddbuf;

	mbr_signature = boot_params.edd_mbr_sig_buffer;



	op.cmd = XENPF_firmware_info;



	op.u.firmware_info.type = XEN_FW_DISK_INFO;

	for (nr = 0; nr < EDDMAXNR; nr++) {

		struct edd_info *info = edd_info + nr;



		op.u.firmware_info.index = nr;

		info->params.length = sizeof(info->params);

		set_xen_guest_handle(op.u.firmware_info.u.disk_info.edd_params,

				     &info->params);

		ret = HYPERVISOR_dom0_op(&op);

		if (ret)

			break;



#define C(x) info->x = op.u.firmware_info.u.disk_info.x

		C(device);

		C(version);

		C(interface_support);

		C(legacy_max_cylinder);

		C(legacy_max_head);

		C(legacy_sectors_per_track);

#undef C

	}

	boot_params.eddbuf_entries = nr;



	op.u.firmware_info.type = XEN_FW_DISK_MBR_SIGNATURE;

	for (nr = 0; nr < EDD_MBR_SIG_MAX; nr++) {

		op.u.firmware_info.index = nr;

		ret = HYPERVISOR_dom0_op(&op);

		if (ret)

			break;

		mbr_signature[nr] = op.u.firmware_info.u.disk_mbr_signature.mbr_signature;

	}

	boot_params.edd_mbr_sig_buf_entries = nr;

#endif

}



/*

 * Set up the GDT and segment registers for -fstack-protector.  Until

 * we do this, we have to be careful not to call any stack-protected
@@ -1508,6 +1558,8 @@ asmlinkage void __init xen_start_kernel(void) 
		/* Avoid searching for BIOS MP tables */

		x86_init.mpparse.find_smp_config = x86_init_noop;

		x86_init.mpparse.get_smp_config = x86_init_uint_noop;



		xen_boot_params_init_edd();

	}

#ifdef CONFIG_PCI

	/* PCI BIOS service won't work from a PV guest. */