Introduce a Meson feature option and default-config entry to allow
building QEMU with MSHV (Microsoft Hypervisor) acceleration support.

This is the first step toward implementing an MSHV backend in QEMU.

Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com>
---
 accel/Kconfig                 |  3 +++
 meson.build                   | 10 ++++++++++
 meson_options.txt             |  2 ++
 scripts/meson-buildoptions.sh |  3 +++
 4 files changed, 18 insertions(+)

diff --git a/accel/Kconfig b/accel/Kconfig
index 4263cab722..a60f114923 100644
--- a/accel/Kconfig
+++ b/accel/Kconfig
@@ -13,6 +13,9 @@ config TCG
 config KVM
     bool
 
+config MSHV
+    bool
+
 config XEN
     bool
     select FSDEV_9P if VIRTFS
diff --git a/meson.build b/meson.build
index dbc97bfdf7..927f3474ea 100644
--- a/meson.build
+++ b/meson.build
@@ -334,6 +334,7 @@ elif cpu == 'x86_64'
     'CONFIG_HVF': ['x86_64-softmmu'],
     'CONFIG_NVMM': ['i386-softmmu', 'x86_64-softmmu'],
     'CONFIG_WHPX': ['i386-softmmu', 'x86_64-softmmu'],
+    'CONFIG_MSHV': ['x86_64-softmmu'],
   }
 endif
 
@@ -884,6 +885,14 @@ accelerators = []
 if get_option('kvm').allowed() and host_os == 'linux'
   accelerators += 'CONFIG_KVM'
 endif
+
+if get_option('mshv').allowed() and host_os == 'linux'
+  if get_option('mshv').enabled() and host_machine.cpu() != 'x86_64'
+    error('mshv accelerator requires x64_64 host')
+  endif
+  accelerators += 'CONFIG_MSHV'
+endif
+
 if get_option('whpx').allowed() and host_os == 'windows'
   if get_option('whpx').enabled() and host_machine.cpu() != 'x86_64'
     error('WHPX requires 64-bit host')
@@ -4797,6 +4806,7 @@ if have_system
   summary_info += {'HVF support':       config_all_accel.has_key('CONFIG_HVF')}
   summary_info += {'WHPX support':      config_all_accel.has_key('CONFIG_WHPX')}
   summary_info += {'NVMM support':      config_all_accel.has_key('CONFIG_NVMM')}
+  summary_info += {'MSHV support':       config_all_accel.has_key('CONFIG_MSHV')}
   summary_info += {'Xen support':       xen.found()}
   if xen.found()
     summary_info += {'xen ctrl version':  xen.version()}
diff --git a/meson_options.txt b/meson_options.txt
index a442be2995..1c02a4f54b 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -71,6 +71,8 @@ option('malloc', type : 'combo', choices : ['system', 'tcmalloc', 'jemalloc'],
 
 option('kvm', type: 'feature', value: 'auto',
        description: 'KVM acceleration support')
+option('mshv', type: 'feature', value: 'auto',
+       description: 'MSHV acceleration support')
 option('whpx', type: 'feature', value: 'auto',
        description: 'WHPX acceleration support')
 option('hvf', type: 'feature', value: 'auto',
diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
index 73e0770f42..d21bf4dc33 100644
--- a/scripts/meson-buildoptions.sh
+++ b/scripts/meson-buildoptions.sh
@@ -153,6 +153,7 @@ meson_options_help() {
   printf "%s\n" '  membarrier      membarrier system call (for Linux 4.14+ or Windows'
   printf "%s\n" '  modules         modules support (non Windows)'
   printf "%s\n" '  mpath           Multipath persistent reservation passthrough'
+  printf "%s\n" '  mshv            MSHV acceleration support'
   printf "%s\n" '  multiprocess    Out of process device emulation support'
   printf "%s\n" '  netmap          netmap network backend support'
   printf "%s\n" '  nettle          nettle cryptography support'
@@ -404,6 +405,8 @@ _meson_option_parse() {
     --disable-modules) printf "%s" -Dmodules=disabled ;;
     --enable-mpath) printf "%s" -Dmpath=enabled ;;
     --disable-mpath) printf "%s" -Dmpath=disabled ;;
+    --enable-mshv) printf "%s" -Dmshv=enabled ;;
+    --disable-mshv) printf "%s" -Dmshv=disabled ;;
     --enable-multiprocess) printf "%s" -Dmultiprocess=enabled ;;
     --disable-multiprocess) printf "%s" -Dmultiprocess=disabled ;;
     --enable-netmap) printf "%s" -Dnetmap=enabled ;;
-- 
2.34.1