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: David Vrabel <david.vrabel@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index c8e1c7b..47d3243 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -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 @@
.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 @@
/* 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. */