Hi Boris,
On 20/01/2021 22:49, Boris Ostrovsky wrote:
This option allows guest administrator specify what should happen when
guest accesses an MSR which is not explicitly emulated by the hypervisor.
Signed-off-by: Boris Ostrovsky <boris.ostrov...@oracle.com>
---
docs/man/xl.cfg.5.pod.in | 20 +++++++++++++++++++-
tools/libs/light/libxl_types.idl | 7 +++++++
tools/xl/xl_parse.c | 7 +++++++
3 files changed, 33 insertions(+), 1 deletion(-)
diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
index c8e017f950de..96ce97c42cab 100644
--- a/docs/man/xl.cfg.5.pod.in
+++ b/docs/man/xl.cfg.5.pod.in
@@ -2044,7 +2044,25 @@ Do not provide a VM generation ID.
See also "Virtual Machine Generation ID" by Microsoft:
L<https://docs.microsoft.com/en-us/windows/win32/hyperv_v2/virtual-machine-generation-identifier>
-=back
+=over
+
+=item B<ignore_msrs="STRING">
+
+Determine hypervisor behavior on accesses to MSRs that are not emulated by the
hypervisor.
The description of the feature looks very x86 focus. Yet, it seems to be
defined as a generic one.
Could you clarify whether this is intended to be re-usable by other
architectures?
+
+=over 4
+
+=item B<never>
+
+Issue a warning to the log and #GP to the guest. This is default.
+
+=item B<silent>
+
+MSR reads return 0, MSR writes are ignored. No warnings to the log.
+
+=item B<verbose>
+
+Similar to B<silent> but a warning is written.
=head3 Guest Virtual Time Controls
diff --git a/tools/libs/light/libxl_types.idl b/tools/libs/light/libxl_types.idl
index 05324736b744..7b5fef771ee8 100644
--- a/tools/libs/light/libxl_types.idl
+++ b/tools/libs/light/libxl_types.idl
@@ -477,6 +477,12 @@ libxl_tee_type = Enumeration("tee_type", [
(1, "optee")
], init_val = "LIBXL_TEE_TYPE_NONE")
+libxl_ignore_msrs = Enumeration("ignore_msrs", [
+ (0, "never"),
+ (1, "silent"),
+ (2, "verbose"),
+ ], init_val = "LIBXL_IGNORE_MSRS_NEVER")
+
libxl_rdm_reserve = Struct("rdm_reserve", [
("strategy", libxl_rdm_reserve_strategy),
("policy", libxl_rdm_reserve_policy),
@@ -559,6 +565,7 @@ libxl_domain_build_info = Struct("domain_build_info",[
("apic", libxl_defbool),
("dm_restrict", libxl_defbool),
("tee", libxl_tee_type),
+ ("ignore_msrs", libxl_ignore_msrs),
("u", KeyedUnion(None, libxl_domain_type, "type",
[("hvm", Struct(None, [("firmware", string),
("bios", libxl_bios_type),
diff --git a/tools/xl/xl_parse.c b/tools/xl/xl_parse.c
index 4ebf39620ae7..942086c3f41d 100644
--- a/tools/xl/xl_parse.c
+++ b/tools/xl/xl_parse.c
@@ -2732,6 +2732,13 @@ skip_usbdev:
}
}
+ if (!xlu_cfg_get_string(config, "ignore_msrs", &buf, 0)) {
+ if (libxl_ignore_msrs_from_string(buf, &b_info->ignore_msrs)) {
+ fprintf(stderr, "ERROR: invalid value \"%s\" for
\"ignore_msrs\"\n", buf);
+ exit(1);
+ }
+ }
+
parse_vkb_list(config, d_config);
xlu_cfg_get_defbool(config, "xend_suspend_evtchn_compat",
Cheers,
--
Julien Grall