Messages in this thread Patch in this message | | | Date | Wed, 25 Apr 2018 12:08:35 +0200 | From | Petr Tesarik <> | Subject | [PATCH] x86: Do not reserve a crash kernel region if booted on Xen PV |
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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> --- arch/x86/kernel/setup.c | 6 ++++++ 1 file changed, 6 insertions(+)
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) { /* -- 2.13.6
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