Merge branch 'xenfv-kvm-15' of git://git.infradead.org/users/dwmw2/qemu into HEAD

This adds support for emulating Xen under Linux/KVM, based on kernel
patches which have been present since Linux v5.12. As with the kernel
support, it's derived from work started by João Martins of Oracle in
2018.

This series just adds the basic platform support — CPUID, hypercalls,
event channels, a stub of XenStore.

A full single-tenant internal implementation of XenStore, and patches
to make QEMU's Xen PV drivers work with this Xen emulation, are waiting
in the wings to be submitted in a follow-on patch series.

As noted in the documentation, it's enabled by setting the xen-version
property on the KVM accelerator, e.g.:

 qemu-system-x86_64 -serial mon:stdio -M q35 -display none -m 1G -smp 2 \
    -accel kvm,xen-version=0x4000e,kernel-irqchip=split \
    -kernel vmlinuz-6.0.7-301.fc37.x86_64 \
    -append "console=ttyS0 root=/dev/sda1" \
    -drive file=/var/lib/libvirt/images/fedora28.qcow2,if=none,id=disk \
    -device ahci,id=ahci -device ide-hd,drive=disk,bus=ahci.0

Even before this was merged, we've already been using it to find and fix
bugs in the Linux kernel Xen guest support:

https://lore.kernel.org/all/4bffa69a949bfdc92c4a18e5a1c3cbb3b94a0d32.camel@infradead.org/
https://lore.kernel.org/all/871qnunycr.ffs@tglx/

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

5 files changed, 48 insertions, 38 deletions

diff --git a/dump/dump-hmp-cmds.c b/dump/dump-hmp-cmds.c
index e5053b04cd..b038785fee 100644
--- a/dump/dump-hmp-cmds.c
+++ b/dump/dump-hmp-cmds.c
@@ -1,5 +1,5 @@
 /*
- * Human Monitor Interface commands
+ * Windows crashdump (Human Monitor Interface commands)
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
diff --git a/dump/dump.c b/dump/dump.c
index 1362810991..544d5bce3a 100644
--- a/dump/dump.c
+++ b/dump/dump.c
@@ -14,25 +14,21 @@
 #include "qemu/osdep.h"
 #include "qemu/cutils.h"
 #include "elf.h"
-#include "exec/hwaddr.h"
+#include "qemu/bswap.h"
+#include "exec/target_page.h"
 #include "monitor/monitor.h"
-#include "sysemu/kvm.h"
 #include "sysemu/dump.h"
-#include "sysemu/memory_mapping.h"
 #include "sysemu/runstate.h"
 #include "sysemu/cpus.h"
 #include "qapi/error.h"
 #include "qapi/qapi-commands-dump.h"
 #include "qapi/qapi-events-dump.h"
 #include "qapi/qmp/qerror.h"
-#include "qemu/error-report.h"
 #include "qemu/main-loop.h"
 #include "hw/misc/vmcoreinfo.h"
 #include "migration/blocker.h"
-
-#ifdef TARGET_X86_64
+#include "hw/core/cpu.h"
 #include "win_dump.h"
-#endif
 
 #include <zlib.h>
 #ifdef CONFIG_LZO
@@ -907,13 +903,13 @@ static void get_note_sizes(DumpState *s, const void *note,
     if (dump_is_64bit(s)) {
         const Elf64_Nhdr *hdr = note;
         note_head_sz = sizeof(Elf64_Nhdr);
-        name_sz = tswap64(hdr->n_namesz);
-        desc_sz = tswap64(hdr->n_descsz);
+        name_sz = cpu_to_dump64(s, hdr->n_namesz);
+        desc_sz = cpu_to_dump64(s, hdr->n_descsz);
     } else {
         const Elf32_Nhdr *hdr = note;
         note_head_sz = sizeof(Elf32_Nhdr);
-        name_sz = tswap32(hdr->n_namesz);
-        desc_sz = tswap32(hdr->n_descsz);
+        name_sz = cpu_to_dump32(s, hdr->n_namesz);
+        desc_sz = cpu_to_dump32(s, hdr->n_descsz);
     }
 
     if (note_head_size) {
@@ -1860,7 +1856,7 @@ static void dump_init(DumpState *s, int fd, bool has_format,
     }
 
     if (!s->dump_info.page_size) {
-        s->dump_info.page_size = TARGET_PAGE_SIZE;
+        s->dump_info.page_size = qemu_target_page_size();
     }
 
     s->note_size = cpu_get_note_size(s->dump_info.d_class,
@@ -2022,9 +2018,7 @@ static void dump_process(DumpState *s, Error **errp)
     DumpQueryResult *result = NULL;
 
     if (s->has_format && s->format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP) {
-#ifdef TARGET_X86_64
         create_win_dump(s, errp);
-#endif
     } else if (s->has_format && s->format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
         create_kdump_vmcore(s, errp);
     } else {
@@ -2127,12 +2121,10 @@ void qmp_dump_guest_memory(bool paging, const char *file,
     }
 #endif
 
-#ifndef TARGET_X86_64
-    if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP) {
-        error_setg(errp, "Windows dump is only available for x86-64");
+    if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP
+        && !win_dump_available(errp)) {
         return;
     }
-#endif
 
 #if !defined(WIN32)
     if (strstart(file, "fd:", &p)) {
@@ -2214,10 +2206,9 @@ DumpGuestMemoryCapability *qmp_query_dump_guest_memory_capability(Error **errp)
     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY);
 #endif
 
-    /* Windows dump is available only if target is x86_64 */
-#ifdef TARGET_X86_64
-    QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_WIN_DMP);
-#endif
+    if (win_dump_available(NULL)) {
+        QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_WIN_DMP);
+    }
 
     return cap;
 }
diff --git a/dump/meson.build b/dump/meson.build
index 2eff29c3ea..df52ee4268 100644
--- a/dump/meson.build
+++ b/dump/meson.build
@@ -1,4 +1,2 @@
-softmmu_ss.add(files('dump-hmp-cmds.c'))
-
-specific_ss.add(when: 'CONFIG_SOFTMMU', if_true: [files('dump.c'), snappy, lzo])
-specific_ss.add(when: ['CONFIG_SOFTMMU', 'TARGET_X86_64'], if_true: files('win_dump.c'))
+softmmu_ss.add([files('dump.c', 'dump-hmp-cmds.c'), snappy, lzo])
+specific_ss.add(when: 'CONFIG_SOFTMMU', if_true: files('win_dump.c'))
diff --git a/dump/win_dump.c b/dump/win_dump.c
index f20b6051b6..0152f7330a 100644
--- a/dump/win_dump.c
+++ b/dump/win_dump.c
@@ -1,5 +1,5 @@
 /*
- * Windows crashdump
+ * Windows crashdump (target specific implementations)
  *
  * Copyright (c) 2018 Virtuozzo International GmbH
  *
@@ -9,19 +9,21 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu/cutils.h"
-#include "elf.h"
-#include "exec/hwaddr.h"
-#include "monitor/monitor.h"
-#include "sysemu/kvm.h"
 #include "sysemu/dump.h"
-#include "sysemu/memory_mapping.h"
-#include "sysemu/cpus.h"
 #include "qapi/error.h"
 #include "qapi/qmp/qerror.h"
-#include "qemu/error-report.h"
-#include "hw/misc/vmcoreinfo.h"
+#include "exec/cpu-defs.h"
+#include "hw/core/cpu.h"
+#include "qemu/win_dump_defs.h"
 #include "win_dump.h"
+#include "cpu.h"
+
+#if defined(TARGET_X86_64)
+
+bool win_dump_available(Error **errp)
+{
+    return true;
+}
 
 static size_t win_dump_ptr_size(bool x64)
 {
@@ -475,3 +477,19 @@ out_cr3:
 
     return;
 }
+
+#else /* !TARGET_X86_64 */
+
+bool win_dump_available(Error **errp)
+{
+    error_setg(errp, "Windows dump is only available for x86-64");
+
+    return false;
+}
+
+void create_win_dump(DumpState *s, Error **errp)
+{
+    win_dump_available(errp);
+}
+
+#endif
diff --git a/dump/win_dump.h b/dump/win_dump.h
index b8c25348f4..c9b49f87dc 100644
--- a/dump/win_dump.h
+++ b/dump/win_dump.h
@@ -11,7 +11,10 @@
 #ifndef WIN_DUMP_H
 #define WIN_DUMP_H
 
-#include "qemu/win_dump_defs.h"
+#include "sysemu/dump.h"
+
+/* Check Windows dump availability for the current target */
+bool win_dump_available(Error **errp);
 
 void create_win_dump(DumpState *s, Error **errp);