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authorPetr Tesarik <ptesarik@suse.cz>2018-04-25 12:08:35 +0200
committerThomas Gleixner <tglx@linutronix.de>2018-04-27 17:06:28 +0200
commit3db3eb285259ac129f7aec6b814b3e9f6c1b372b (patch)
tree4d5bc5058ead6a13380ac4ecbf64f54b7b6347e0 /arch/x86/kernel
parentb837913fc2d9061bf9b8c0dd6bf2d24e2f98b84a (diff)
x86/setup: Do not reserve a crash kernel region if booted on Xen PV
Xen PV domains cannot shut down and start a crash kernel. Instead, the crashing kernel makes a SCHEDOP_shutdown hypercall with the reason code SHUTDOWN_crash, cf. xen_crash_shutdown() machine op in arch/x86/xen/enlighten_pv.c. A crash kernel reservation is merely a waste of RAM in this case. It may also confuse users of kexec_load(2) and/or kexec_file_load(2). When flags include KEXEC_ON_CRASH or KEXEC_FILE_ON_CRASH, respectively, these syscalls return success, which is technically correct, but the crash kexec image will never be actually used. Signed-off-by: Petr Tesarik <ptesarik@suse.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Dou Liyang <douly.fnst@cn.fujitsu.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: xen-devel@lists.xenproject.org Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@suse.de> Cc: Jean Delvare <jdelvare@suse.de> Link: https://lkml.kernel.org/r/20180425120835.23cef60c@ezekiel.suse.cz
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/setup.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 6285697b6e56..5c623dfe39d1 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -50,6 +50,7 @@
#include <linux/init_ohci1394_dma.h>
#include <linux/kvm_para.h>
#include <linux/dma-contiguous.h>
+#include <xen/xen.h>
#include <linux/errno.h>
#include <linux/kernel.h>
@@ -534,6 +535,11 @@ static void __init reserve_crashkernel(void)
high = true;
}
+ if (xen_pv_domain()) {
+ pr_info("Ignoring crashkernel for a Xen PV domain\n");
+ return;
+ }
+
/* 0 means: find the address automatically */
if (crash_base <= 0) {
/*