git: a2495c36678c - main - xen/boot: allow specifying boot method when booted from Xen

[Roger Pau Monné]

The branch main has been updated by royger:

URL: https://cgit.FreeBSD.org/src/commit/?id=a2495c36678cb16597758ce150da5456cdd90331

commit a2495c36678cb16597758ce150da5456cdd90331
Author:     Roger Pau Monné <royger at FreeBSD.org>
AuthorDate: 2021-02-08 10:28:36 +0000
Commit:     Roger Pau Monné <royger at FreeBSD.org>
CommitDate: 2021-02-16 14:26:11 +0000

    xen/boot: allow specifying boot method when booted from Xen
    
    Allow setting the bootmethod variable from the Xen PVH entry point, in
    order to be able to correctly set the underlying firmware mode when
    booted as a dom0.
    
    Move the bootmethod variable to be defined in x86/cpu_machdep.c
    instead so it can be shared by both i386 and amd64.
    
    Sponsored by:           Citrix Systems R&D
    Reviewed by:            kib
    Differential revision:  https://reviews.freebsd.org/D28619
---
 sys/amd64/amd64/machdep.c | 4 ----
 sys/i386/i386/machdep.c   | 7 +++----
 sys/x86/include/x86_var.h | 1 +
 sys/x86/x86/cpu_machdep.c | 4 ++++
 sys/x86/xen/pv.c          | 8 ++++++++
 5 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index a21a93610e51..569e32207a2c 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -1169,10 +1169,6 @@ add_efi_map_entries(struct efi_map_header *efihdr, vm_paddr_t *physmap,
 	}
 }
 
-static char bootmethod[16] = "";
-SYSCTL_STRING(_machdep, OID_AUTO, bootmethod, CTLFLAG_RD, bootmethod, 0,
-    "System firmware boot method");
-
 static void
 native_parse_memmap(caddr_t kmdp, vm_paddr_t *physmap, int *physmap_idx)
 {
diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index e847d97b8bcf..a9749d331f89 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -1237,10 +1237,6 @@ u_long bootdev;		/* not a struct cdev *- encoding is different */
 SYSCTL_ULONG(_machdep, OID_AUTO, guessed_bootdev,
 	CTLFLAG_RD, &bootdev, 0, "Maybe the Boot device (not in struct cdev *format)");
 
-static char bootmethod[16] = "BIOS";
-SYSCTL_STRING(_machdep, OID_AUTO, bootmethod, CTLFLAG_RD, bootmethod, 0,
-    "System firmware boot method");
-
 /*
  * Initialize 386 and configure to run kernel
  */
@@ -2348,6 +2344,9 @@ init386(int first)
 	/* Init basic tunables, hz etc */
 	init_param1();
 
+	/* Set bootmethod to BIOS: it's the only supported on i386. */
+	strlcpy(bootmethod, "BIOS", sizeof(bootmethod));
+
 	/*
 	 * Make gdt memory segments.  All segments cover the full 4GB
 	 * of address space and permissions are enforced at page level.
diff --git a/sys/x86/include/x86_var.h b/sys/x86/include/x86_var.h
index c1425755b5d1..f31dcd47fff5 100644
--- a/sys/x86/include/x86_var.h
+++ b/sys/x86/include/x86_var.h
@@ -95,6 +95,7 @@ extern	int	x86_taa_enable;
 extern	int	cpu_flush_rsb_ctxsw;
 extern	int	x86_rngds_mitg_enable;
 extern	int	cpu_amdc1e_bug;
+extern	char	bootmethod[16];
 
 struct	pcb;
 struct	thread;
diff --git a/sys/x86/x86/cpu_machdep.c b/sys/x86/x86/cpu_machdep.c
index 4798f913d5b2..5bac8eb91eac 100644
--- a/sys/x86/x86/cpu_machdep.c
+++ b/sys/x86/x86/cpu_machdep.c
@@ -111,6 +111,10 @@ static u_int	cpu_reset_proxyid;
 static volatile u_int	cpu_reset_proxy_active;
 #endif
 
+char bootmethod[16];
+SYSCTL_STRING(_machdep, OID_AUTO, bootmethod, CTLFLAG_RD, bootmethod, 0,
+    "System firmware boot method");
+
 struct msr_op_arg {
 	u_int msr;
 	int op;
diff --git a/sys/x86/xen/pv.c b/sys/x86/xen/pv.c
index 2fd698772f9d..a2424423aded 100644
--- a/sys/x86/xen/pv.c
+++ b/sys/x86/xen/pv.c
@@ -48,6 +48,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/ctype.h>
 #include <sys/mutex.h>
 #include <sys/smp.h>
+#include <sys/efi.h>
 
 #include <vm/vm.h>
 #include <vm/vm_extern.h>
@@ -65,6 +66,7 @@ __FBSDID("$FreeBSD$");
 #include <machine/pc/bios.h>
 #include <machine/smp.h>
 #include <machine/intr_machdep.h>
+#include <machine/md_var.h>
 #include <machine/metadata.h>
 
 #include <xen/xen-os.h>
@@ -630,6 +632,11 @@ xen_pvh_parse_preload_data(uint64_t modulep)
 		if (envp != NULL)
 			envp += off;
 		xen_pvh_set_env(envp, reject_option);
+
+		if (MD_FETCH(kmdp, MODINFOMD_EFI_MAP, void *) != NULL)
+		    strlcpy(bootmethod, "UEFI", sizeof(bootmethod));
+		else
+		    strlcpy(bootmethod, "BIOS", sizeof(bootmethod));
 	} else {
 		/* Parse the extra boot information given by Xen */
 		if (start_info->cmdline_paddr != 0)
@@ -637,6 +644,7 @@ xen_pvh_parse_preload_data(uint64_t modulep)
 			    (char *)(start_info->cmdline_paddr + KERNBASE),
 			    ",");
 		kmdp = NULL;
+		strlcpy(bootmethod, "XEN", sizeof(bootmethod));
 	}
 
 	boothowto |= boot_env_to_howto();