The following commits introduced the time reference counter MSR and
TSC/APIC frequency MSRs into the viridian feature set respectively:
e36cd2cdc9674a7a4855d21fb7b3e6e17c4bb33b
84657efd9116f40924aa13c9d5a349e007da716f
The time reference counter MSR feature was then reverted by commit
1cd4fab14ce25859efa4a2af13475e6650a5506c
because a flaw in the implementation meant the counter was reset on
migration.
All of these changes were made without any addtional options being
added to the VM configuration, or any compatibility checks being made
in the domain save/restore code. Hence setting the single boolean
'viridian' option in the VM configuration yields a different set of
features depending on which version of Xen the VM is started on, and the
feature set can change across migration (so new MSRs can magically appear).
This patch grandfathers in the current viridian features set and calls them
the 'base' and 'freq' feature sets. HVM_PARAM_VIRIDIAN is re-purposed as
a feature mask. The hypervisor has only ever allowed it ot be set to 0
or 1, so the presence of the base and freq sets are indicated by setting
bit 0. The freq set can then be turned off by setting bit 1, thus
restoring the pre-Xen-4.4 base set. Newly implemented viridian features
can be optionally enabled in future by setting further bits.
The viridian option in xl.cfg(5) has also been changed to a list so
that the sets can be individually enabled or disabled. For compatibility,
if the option is specified as a boolean, then a true (1) value will enable
the base and freq sets and a false (0) value will not enable any
enlightenments.
This patch also alters the allowed write accesses to HVM_PARAM_VIRIDIAN.
Currently there is nothing to stop the guest writing this value (which,
while harmless to anything else, should not happen) and nothing to
stop a toolstack from setting the value back to zero whilst the guest is
running, causing CPUID leaves to disappear and MSR accesses to start
causing GPFs in the guest. Both of these possibilities are now disallowed:
Once the parameter is set to a non-zero value it may not be modified (only
re-written with the same value), and guests no longer have any write
access.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Keir Fraser <keir@xen.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: David Scott <dave.scott@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Setting B<xen_platform_pci=0> with the default device_model "qemu-xen"
requires at least QEMU 1.6.
-=item B<viridian=BOOLEAN>
-
-Turns on or off the exposure of MicroSoft Hyper-V (AKA viridian)
-compatible enlightenments to the guest. These can improve performance
-of Microsoft Windows guests from Windows Vista and Windows 2008
-onwards and setting this option for such guests is strongly
-recommended. This option should be harmless for other versions of
-Windows (although it will not give any benefit) and the majority of
-other non-Windows OSes. However it is known to be incompatible with
-some other Operating Systems and in some circumstance can prevent
-Xen's own paravirtualisation interfaces for HVM guests from being
-used.
+=item B<viridian=[ "GROUP", "GROUP", ...]>
+
+The groups of Microsoft Hyper-V (AKA viridian) compatible enlightenments
+exposed to the guest. The following groups of enlightenments may be
+specified:
+
+=over 4
+
+=item B<base>
+
+This group incorporates the Hypercall MSRs, Virtual processor index MSR,
+and APIC access MSRs. These enlightenments can improve performance of
+Windows Vista and Windows Server 2008 onwards and setting this option
+for such guests is strongly recommended.
+This group is also a pre-requisite for all others. If it is disabled
+then it is an error to attempt to enable any other group.
+
+=item B<freq>
+
+This group incorporates the TSC and APIC frequency MSRs. These
+enlightenments can improve performance of Windows 7 and Windows
+Server 2008 R2 onwards.
+
+=item B<defaults>
+
+This is a special value that enables the default set of groups, which
+is currently the B<base> and B<freq> groups.
+
+=item B<all>
+
+This is a special value that enables all available groups.
+
+=back
+
+Groups can be disabled by prefixing the name with '!'. So, for example,
+to enable all groups except B<freq>, specify:
+
+=over 4
+
+B<viridian=[ "all", "!freq" ]>
+
+=back
+
+For details of the enlightenments see the latest version of Microsoft's
+Hypervisor Top-Level Functional Specification.
+
+The enlightenments should be harmless for other versions of Windows
+(although they will not give any benefit) and the majority of other
+non-Windows OSes.
+However it is known that they are incompatible with some other Operating
+Systems and in some circumstance can prevent Xen's own paravirtualisation
+interfaces for HVM guests from being used.
+
+The viridian option can be specified as a boolean. A value of true (1)
+is equivalent to the list [ "defaults" ], and a value of false (0) is
+equivalent to an empty list.
=back
if ( RDEXACT(fd, &buf->viridian, sizeof(uint32_t)) ||
RDEXACT(fd, &buf->viridian, sizeof(uint64_t)) )
{
- PERROR("error read the viridian flag");
+ PERROR("error reading the viridian enlightenments");
return -1;
}
return pagebuf_get_one(xch, ctx, buf, fd, dom);
}
if (pagebuf.viridian != 0)
- xc_hvm_param_set(xch, dom, HVM_PARAM_VIRIDIAN, 1);
+ xc_hvm_param_set(xch, dom, HVM_PARAM_VIRIDIAN, pagebuf.viridian);
/*
* If we are migrating in from a host that does not support
*/
#define LIBXL_HAVE_SCHED_RTDS 1
+/*
+ * libxl_domain_build_info has u.hvm.viridian_enable and _disable bitmaps
+ * of the specified width.
+ */
+#define LIBXL_HAVE_BUILDINFO_HVM_VIRIDIAN_ENABLE_DISABLE 1
+#define LIBXL_BUILDINFO_HVM_VIRIDIAN_ENABLE_DISABLE_WIDTH 64
+
/*
* libxl ABI compatibility
*
return ((unsigned long)mode);
}
+#if defined(__i386__) || defined(__x86_64__)
+static int hvm_set_viridian_features(libxl__gc *gc, uint32_t domid,
+ libxl_domain_build_info *const info)
+{
+ libxl_bitmap enlightenments;
+ libxl_viridian_enlightenment v;
+ uint64_t mask = 0;
+
+ libxl_bitmap_init(&enlightenments);
+ libxl_bitmap_alloc(CTX, &enlightenments,
+ LIBXL_BUILDINFO_HVM_VIRIDIAN_ENABLE_DISABLE_WIDTH);
+
+ if (libxl_defbool_val(info->u.hvm.viridian)) {
+ /* Enable defaults */
+ libxl_bitmap_set(&enlightenments, LIBXL_VIRIDIAN_ENLIGHTENMENT_BASE);
+ libxl_bitmap_set(&enlightenments, LIBXL_VIRIDIAN_ENLIGHTENMENT_FREQ);
+ }
+
+ libxl_for_each_set_bit(v, info->u.hvm.viridian_enable) {
+ if (libxl_bitmap_test(&info->u.hvm.viridian_disable, v)) {
+ LIBXL__LOG(CTX, LIBXL__LOG_ERROR, "%s group both enabled and disabled",
+ libxl_viridian_enlightenment_to_string(v));
+ goto err;
+ }
+ if (libxl_viridian_enlightenment_to_string(v)) /* check validity */
+ libxl_bitmap_set(&enlightenments, v);
+ }
+
+ libxl_for_each_set_bit(v, info->u.hvm.viridian_disable)
+ if (libxl_viridian_enlightenment_to_string(v)) /* check validity */
+ libxl_bitmap_reset(&enlightenments, v);
+
+ /* The base set is a pre-requisite for all others */
+ if (!libxl_bitmap_is_empty(&enlightenments) &&
+ !libxl_bitmap_test(&enlightenments, LIBXL_VIRIDIAN_ENLIGHTENMENT_BASE)) {
+ LIBXL__LOG(CTX, LIBXL__LOG_ERROR, "base group not enabled");
+ goto err;
+ }
+
+ libxl_for_each_set_bit(v, enlightenments)
+ LOG(DETAIL, "%s group enabled", libxl_viridian_enlightenment_to_string(v));
+
+ if (libxl_bitmap_test(&enlightenments, LIBXL_VIRIDIAN_ENLIGHTENMENT_BASE)) {
+ mask |= HVMPV_base_freq;
+
+ if (!libxl_bitmap_test(&enlightenments, LIBXL_VIRIDIAN_ENLIGHTENMENT_FREQ))
+ mask |= HVMPV_no_freq;
+ }
+
+ if (mask != 0 &&
+ xc_hvm_param_set(CTX->xch,
+ domid,
+ HVM_PARAM_VIRIDIAN,
+ mask) != 0) {
+ LIBXL__LOG_ERRNO(CTX, LIBXL__LOG_ERROR,
+ "Couldn't set viridian feature mask (0x%"PRIx64")",
+ mask);
+ goto err;
+ }
+
+ libxl_bitmap_dispose(&enlightenments);
+ return 0;
+
+err:
+ libxl_bitmap_dispose(&enlightenments);
+ return ERROR_FAIL;
+}
+#endif
+
static void hvm_set_conf_params(xc_interface *handle, uint32_t domid,
libxl_domain_build_info *const info)
{
xc_hvm_param_set(handle, domid, HVM_PARAM_PAE_ENABLED,
libxl_defbool_val(info->u.hvm.pae));
#if defined(__i386__) || defined(__x86_64__)
- xc_hvm_param_set(handle, domid, HVM_PARAM_VIRIDIAN,
- libxl_defbool_val(info->u.hvm.viridian));
xc_hvm_param_set(handle, domid, HVM_PARAM_HPET_ENABLED,
libxl_defbool_val(info->u.hvm.hpet));
#endif
state->store_port = xc_evtchn_alloc_unbound(ctx->xch, domid, state->store_domid);
state->console_port = xc_evtchn_alloc_unbound(ctx->xch, domid, state->console_domid);
- if (info->type == LIBXL_DOMAIN_TYPE_HVM)
+ if (info->type == LIBXL_DOMAIN_TYPE_HVM) {
hvm_set_conf_params(ctx->xch, domid, info);
+#if defined(__i386__) || defined(__x86_64__)
+ rc = hvm_set_viridian_features(gc, domid, info);
+ if (rc)
+ return rc;
+#endif
+ }
rc = libxl__arch_domain_create(gc, d_config, domid);
(0, "NONE"),
(1, "XENSERVER"),
])
+
+libxl_viridian_enlightenment = Enumeration("viridian_enlightenment", [
+ (0, "base"),
+ (1, "freq"),
+ ])
+
#
# Complex libxl types
#
("acpi_s4", libxl_defbool),
("nx", libxl_defbool),
("viridian", libxl_defbool),
+ ("viridian_enable", libxl_bitmap),
+ ("viridian_disable", libxl_bitmap),
("timeoffset", string),
("hpet", libxl_defbool),
("vpt_align", libxl_defbool),
long l;
XLU_Config *config;
XLU_ConfigList *cpus, *vbds, *nics, *pcis, *cvfbs, *cpuids, *vtpms;
- XLU_ConfigList *ioports, *irqs, *iomem;
- int num_ioports, num_irqs, num_iomem, num_cpus;
+ XLU_ConfigList *ioports, *irqs, *iomem, *viridian;
+ int num_ioports, num_irqs, num_iomem, num_cpus, num_viridian;
int pci_power_mgmt = 0;
int pci_msitranslate = 0;
int pci_permissive = 0;
xlu_cfg_get_defbool(config, "acpi_s3", &b_info->u.hvm.acpi_s3, 0);
xlu_cfg_get_defbool(config, "acpi_s4", &b_info->u.hvm.acpi_s4, 0);
xlu_cfg_get_defbool(config, "nx", &b_info->u.hvm.nx, 0);
- xlu_cfg_get_defbool(config, "viridian", &b_info->u.hvm.viridian, 0);
xlu_cfg_get_defbool(config, "hpet", &b_info->u.hvm.hpet, 0);
xlu_cfg_get_defbool(config, "vpt_align", &b_info->u.hvm.vpt_align, 0);
+ switch (xlu_cfg_get_list(config, "viridian",
+ &viridian, &num_viridian, 1))
+ {
+ case 0: /* Success */
+ if (num_viridian) {
+ libxl_bitmap_alloc(ctx, &b_info->u.hvm.viridian_enable,
+ LIBXL_BUILDINFO_HVM_VIRIDIAN_ENABLE_DISABLE_WIDTH);
+ libxl_bitmap_alloc(ctx, &b_info->u.hvm.viridian_disable,
+ LIBXL_BUILDINFO_HVM_VIRIDIAN_ENABLE_DISABLE_WIDTH);
+ }
+ for (i = 0; i < num_viridian; i++) {
+ libxl_viridian_enlightenment v;
+
+ buf = xlu_cfg_get_listitem(viridian, i);
+ if (strcmp(buf, "all") == 0)
+ libxl_bitmap_set_any(&b_info->u.hvm.viridian_enable);
+ else if (strcmp(buf, "defaults") == 0)
+ libxl_defbool_set(&b_info->u.hvm.viridian, true);
+ else {
+ libxl_bitmap *s = &b_info->u.hvm.viridian_enable;
+ libxl_bitmap *r = &b_info->u.hvm.viridian_disable;
+
+ if (*buf == '!') {
+ s = &b_info->u.hvm.viridian_disable;
+ r = &b_info->u.hvm.viridian_enable;
+ buf++;
+ }
+
+ e = libxl_viridian_enlightenment_from_string(buf, &v);
+ if (e) {
+ fprintf(stderr,
+ "xl: unknown viridian enlightenment '%s'\n",
+ buf);
+ exit(-ERROR_FAIL);
+ }
+
+ libxl_bitmap_set(s, v);
+ libxl_bitmap_reset(r, v);
+ }
+ }
+ break;
+ case ESRCH: break; /* Option not present */
+ case EINVAL:
+ xlu_cfg_get_defbool(config, "viridian", &b_info->u.hvm.viridian, 1);
+ break;
+ default:
+ fprintf(stderr,"xl: Unable to parse viridian enlightenments.\n");
+ exit(-ERROR_FAIL);
+ }
+
if (!xlu_cfg_get_long(config, "timer_mode", &l, 1)) {
const char *s = libxl_timer_mode_to_string(l);
fprintf(stderr, "WARNING: specifying \"timer_mode\" as an integer is deprecated. "
rc = -EINVAL;
break;
case HVM_PARAM_VIRIDIAN:
- if ( a.value > 1 )
+ /* This should only ever be set once by the tools and read by the guest. */
+ rc = -EPERM;
+ if ( curr_d == d )
+ break;
+
+ if ( a.value != d->arch.hvm_domain.params[a.index] )
+ {
+ rc = -EEXIST;
+ if ( d->arch.hvm_domain.params[a.index] != 0 )
+ break;
+
rc = -EINVAL;
+ if ( (a.value & ~HVMPV_feature_mask) ||
+ !(a.value & HVMPV_base_freq) )
+ break;
+ }
+
+ rc = 0;
break;
case HVM_PARAM_IDENT_PT:
/* Not reflexive, as we must domain_pause(). */
/* Which hypervisor MSRs are available to the guest */
*eax = (CPUID3A_MSR_APIC_ACCESS |
CPUID3A_MSR_HYPERCALL |
- CPUID3A_MSR_VP_INDEX |
- CPUID3A_MSR_FREQ);
+ CPUID3A_MSR_VP_INDEX);
+ if ( !(viridian_feature_mask(d) & HVMPV_no_freq) )
+ *eax |= CPUID3A_MSR_FREQ;
break;
case 4:
/* Recommended hypercall usage. */
break;
case VIRIDIAN_MSR_TSC_FREQUENCY:
+ if ( viridian_feature_mask(d) & HVMPV_no_freq )
+ return 0;
+
perfc_incr(mshv_rdmsr_tsc_frequency);
*val = (uint64_t)d->arch.tsc_khz * 1000ull;
break;
case VIRIDIAN_MSR_APIC_FREQUENCY:
+ if ( viridian_feature_mask(d) & HVMPV_no_freq )
+ return 0;
+
perfc_incr(mshv_rdmsr_apic_frequency);
*val = 1000000000ull / APIC_BUS_CYCLE_NS;
break;
HVM_REGISTER_SAVE_RESTORE(VIRIDIAN_VCPU, viridian_save_vcpu_ctxt,
viridian_load_vcpu_ctxt, 1, HVMSR_PER_VCPU);
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
return hvm_funcs.get_shadow_gs_base(v);
}
-#define is_viridian_domain(_d) \
- (is_hvm_domain(_d) && ((_d)->arch.hvm_domain.params[HVM_PARAM_VIRIDIAN]))
+#define viridian_feature_mask(d) \
+ ((d)->arch.hvm_domain.params[HVM_PARAM_VIRIDIAN])
+
+#define is_viridian_domain(d) \
+ (is_hvm_domain(d) && (viridian_feature_mask(d) & HVMPV_base_freq))
void hvm_hypervisor_cpuid_leaf(uint32_t sub_idx,
uint32_t *eax, uint32_t *ebx,
#if defined(__i386__) || defined(__x86_64__)
-/* Expose Viridian interfaces to this HVM guest? */
+/*
+ * Viridian enlightenments
+ *
+ * (See http://download.microsoft.com/download/A/B/4/AB43A34E-BDD0-4FA6-BDEF-79EEF16E880B/Hypervisor%20Top%20Level%20Functional%20Specification%20v4.0.docx)
+ *
+ * To expose viridian enlightenments to the guest set this parameter
+ * to the desired feature mask. The base feature set must be present
+ * in any valid feature mask.
+ */
#define HVM_PARAM_VIRIDIAN 9
+/* Base+Freq viridian feature sets:
+ *
+ * - Hypercall MSRs (HV_X64_MSR_GUEST_OS_ID and HV_X64_MSR_HYPERCALL)
+ * - APIC access MSRs (HV_X64_MSR_EOI, HV_X64_MSR_ICR and HV_X64_MSR_TPR)
+ * - Virtual Processor index MSR (HV_X64_MSR_VP_INDEX)
+ * - Timer frequency MSRs (HV_X64_MSR_TSC_FREQUENCY and
+ * HV_X64_MSR_APIC_FREQUENCY)
+ */
+#define _HVMPV_base_freq 0
+#define HVMPV_base_freq (1 << _HVMPV_base_freq)
+
+/* Feature set modifications */
+
+/* Disable timer frequency MSRs (HV_X64_MSR_TSC_FREQUENCY and
+ * HV_X64_MSR_APIC_FREQUENCY).
+ * This modification restores the viridian feature set to the
+ * original 'base' set exposed in releases prior to Xen 4.4.
+ */
+#define _HVMPV_no_freq 1
+#define HVMPV_no_freq (1 << _HVMPV_no_freq)
+
+#define HVMPV_feature_mask (HVMPV_base_freq|HVMPV_no_freq)
+
#endif
/*
projects / xen.git / commitdiff