[src/trunk]: src/sys/arch/xen/x86 avoid excessive stack usage in mp_cpu_start...

[jdolecek <jdolecek%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/d2dbed26cc8b
branches:  trunk
changeset: 935194:d2dbed26cc8b
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Sat Jun 27 09:54:08 2020 +0000

description:
avoid excessive stack usage in mp_cpu_start(), this is called after VM
init so kmem(9) can be used

diffstat:

 sys/arch/xen/x86/cpu.c |  27 ++++++++++++++++-----------
 1 files changed, 16 insertions(+), 11 deletions(-)

diffs (76 lines):

diff -r 544600548aef -r d2dbed26cc8b sys/arch/xen/x86/cpu.c
--- a/sys/arch/xen/x86/cpu.c    Sat Jun 27 09:45:57 2020 +0000
+++ b/sys/arch/xen/x86/cpu.c    Sat Jun 27 09:54:08 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cpu.c,v 1.136 2020/05/21 21:12:31 ad Exp $     */
+/*     $NetBSD: cpu.c,v 1.137 2020/06/27 09:54:08 jdolecek Exp $       */
 
 /*-
  * Copyright (c) 2000 The NetBSD Foundation, Inc.
@@ -65,7 +65,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: cpu.c,v 1.136 2020/05/21 21:12:31 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: cpu.c,v 1.137 2020/06/27 09:54:08 jdolecek Exp $");
 
 #include "opt_ddb.h"
 #include "opt_multiprocessor.h"
@@ -999,22 +999,24 @@
 mp_cpu_start(struct cpu_info *ci, vaddr_t target)
 {
        int hyperror;
-       struct vcpu_guest_context vcpuctx;
+       struct vcpu_guest_context *vcpuctx;
 
        KASSERT(ci != NULL);
        KASSERT(ci != &cpu_info_primary);
        KASSERT(ci->ci_flags & CPUF_AP);
 
+       vcpuctx = kmem_alloc(sizeof(*vcpuctx), KM_SLEEP);
+
 #ifdef __x86_64__
-       xen_init_amd64_vcpuctxt(ci, &vcpuctx, (void (*)(struct cpu_info *))target);
+       xen_init_amd64_vcpuctxt(ci, vcpuctx, (void (*)(struct cpu_info *))target);
 #else
-       xen_init_i386_vcpuctxt(ci, &vcpuctx, (void (*)(struct cpu_info *))target);
+       xen_init_i386_vcpuctxt(ci, vcpuctx, (void (*)(struct cpu_info *))target);
 #endif
 
        /* Initialise the given vcpu to execute cpu_hatch(ci); */
-       if ((hyperror = HYPERVISOR_vcpu_op(VCPUOP_initialise, ci->ci_vcpuid, &vcpuctx))) {
+       if ((hyperror = HYPERVISOR_vcpu_op(VCPUOP_initialise, ci->ci_vcpuid, vcpuctx))) {
                aprint_error(": context initialisation failed. errno = %d\n", hyperror);
-               return hyperror;
+               goto out;
        }
 
        /* Start it up */
@@ -1022,20 +1024,23 @@
        /* First bring it down */
        if ((hyperror = HYPERVISOR_vcpu_op(VCPUOP_down, ci->ci_vcpuid, NULL))) {
                aprint_error(": VCPUOP_down hypervisor command failed. errno = %d\n", hyperror);
-               return hyperror;
+               goto out;
        }
 
        if ((hyperror = HYPERVISOR_vcpu_op(VCPUOP_up, ci->ci_vcpuid, NULL))) {
                aprint_error(": VCPUOP_up hypervisor command failed. errno = %d\n", hyperror);
-               return hyperror;
+               goto out;
        }
 
        if (!vcpu_is_up(ci)) {
                aprint_error(": did not come up\n");
-               return -1;
+               hyperror = -1;
+               goto out;
        }
 
-       return 0;
+out:
+       kmem_free(vcpuctx, sizeof(*vcpuctx));
+       return hyperror;
 }
 
 void