Merge: Refresh s390x KVM subsystem up to kernel 6.17-rc7 and fix postcopy migration problem

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-10/-/merge_requests/1477

JIRA: https://issues.redhat.com/browse/RHEL-113440

JIRA: https://issues.redhat.com/browse/RHEL-42486

Refresh the zKVM subsystem to the latest upstream kernel and fix one important bug with postcopy migration.

Signed-off-by: Thomas Huth <thuth@redhat.com>

Approved-by: Eder Zulian <ezulian@redhat.com>
Approved-by: Rafael Aquini <raquini@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: CKI GitLab Kmaint Pipeline Bot <26919896-cki-kmaint-pipeline-bot@users.noreply.gitlab.com>

Author: CKI KWF Bot

MAINTAINERS

@@ -12626,12 +12626,14 @@ S:	Supported
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git
 F:	Documentation/virt/kvm/s390*
 F:	arch/s390/include/asm/gmap.h
+F:	arch/s390/include/asm/gmap_helpers.h
 F:	arch/s390/include/asm/kvm*
 F:	arch/s390/include/uapi/asm/kvm*
 F:	arch/s390/include/uapi/asm/uvdevice.h
 F:	arch/s390/kernel/uv.c
 F:	arch/s390/kvm/
 F:	arch/s390/mm/gmap.c
+F:	arch/s390/mm/gmap_helpers.c
 F:	drivers/s390/char/uvdevice.c
 F:	tools/testing/selftests/drivers/s390x/uvdevice/
 F:	tools/testing/selftests/kvm/*/s390/

arch/s390/Kconfig

@@ -64,7 +64,6 @@ config S390
 	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
 	select ALTERNATE_USER_ADDRESS_SPACE
 	select ARCH_32BIT_USTAT_F_TINODE
-	select ARCH_BINFMT_ELF_STATE
 	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
 	select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM
 	select ARCH_ENABLE_MEMORY_HOTREMOVE

arch/s390/include/asm/elf.h

@@ -158,9 +158,6 @@ enum {
 #define ELF_DATA	ELFDATA2MSB
 #define ELF_ARCH	EM_S390
 
-/* s390 specific phdr types */
-#define PT_S390_PGSTE	0x70000000
-
 /*
  * ELF register definitions..
  */
@@ -191,35 +188,6 @@ typedef s390_compat_regs compat_elf_gregset_t;
 	 && (x)->e_ident[EI_CLASS] == ELF_CLASS)
 #define compat_start_thread	start_thread31
 
-struct arch_elf_state {
-	int rc;
-};
-
-#define INIT_ARCH_ELF_STATE { .rc = 0 }
-
-#define arch_check_elf(ehdr, interp, interp_ehdr, state) (0)
-#ifdef CONFIG_PGSTE
-#define arch_elf_pt_proc(ehdr, phdr, elf, interp, state)	\
-({								\
-	struct arch_elf_state *_state = state;			\
-	if ((phdr)->p_type == PT_S390_PGSTE &&			\
-	    !page_table_allocate_pgste &&			\
-	    !test_thread_flag(TIF_PGSTE) &&			\
-	    !current->mm->context.alloc_pgste) {		\
-		set_thread_flag(TIF_PGSTE);			\
-		set_pt_regs_flag(task_pt_regs(current),		\
-				 PIF_EXECVE_PGSTE_RESTART);	\
-		_state->rc = -EAGAIN;				\
-	}							\
-	_state->rc;						\
-})
-#else
-#define arch_elf_pt_proc(ehdr, phdr, elf, interp, state)	\
-({								\
-	(state)->rc;						\
-})
-#endif
-
 /* For SVR4/S390 the function pointer to be registered with `atexit` is
    passed in R14. */
 #define ELF_PLAT_INIT(_r, load_addr) \

arch/s390/include/asm/entry-common.h

@@ -59,4 +59,14 @@ static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
 
 #define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare
 
+static __always_inline bool arch_in_rcu_eqs(void)
+{
+	if (IS_ENABLED(CONFIG_KVM))
+		return current->flags & PF_VCPU;
+
+	return false;
+}
+
+#define arch_in_rcu_eqs arch_in_rcu_eqs
+
 #endif

arch/s390/include/asm/gmap.h

@@ -110,7 +110,6 @@ int gmap_map_segment(struct gmap *gmap, unsigned long from,
 int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len);
 unsigned long __gmap_translate(struct gmap *, unsigned long gaddr);
 int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr);
-void gmap_discard(struct gmap *, unsigned long from, unsigned long to);
 void __gmap_zap(struct gmap *, unsigned long gaddr);
 void gmap_unlink(struct mm_struct *, unsigned long *table, unsigned long vmaddr);
 
@@ -134,7 +133,6 @@ int gmap_protect_one(struct gmap *gmap, unsigned long gaddr, int prot, unsigned
 
 void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long dirty_bitmap[4],
 			     unsigned long gaddr, unsigned long vmaddr);
-int s390_disable_cow_sharing(void);
 int s390_replace_asce(struct gmap *gmap);
 void s390_uv_destroy_pfns(unsigned long count, unsigned long *pfns);
 int __s390_uv_destroy_range(struct mm_struct *mm, unsigned long start,

arch/s390/include/asm/gmap_helpers.h

@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  Helper functions for KVM guest address space mapping code
+ *
+ *    Copyright IBM Corp. 2025
+ */
+
+#ifndef _ASM_S390_GMAP_HELPERS_H
+#define _ASM_S390_GMAP_HELPERS_H
+
+void gmap_helper_zap_one_page(struct mm_struct *mm, unsigned long vmaddr);
+void gmap_helper_discard(struct mm_struct *mm, unsigned long vmaddr, unsigned long end);
+int gmap_helper_disable_cow_sharing(void);
+
+#endif /* _ASM_S390_GMAP_HELPERS_H */