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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v10 1/2] x86/viridian: Re-purpose the HVM parameter to be a feature mask
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@xxxxxxxxxx> Cc: Keir Fraser <keir@xxxxxxx> Acked-by: Jan Beulich <jbeulich@xxxxxxxx> Cc: Ian Campbell <ian.campbell@xxxxxxxxxx> Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx> Cc: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> Cc: David Scott <dave.scott@xxxxxxxxxxxxx> --- docs/man/xl.cfg.pod.5 | 65 +++++++++++++++++++++++++++++++-------- tools/libxc/xc_domain_restore.c | 4 +-- tools/libxl/gentypes.py | 6 ++++ tools/libxl/idl.py | 6 ++++ tools/libxl/libxl.h | 5 +++ tools/libxl/libxl_dom.c | 62 +++++++++++++++++++++++++++++++++++-- tools/libxl/libxl_types.idl | 8 +++++ tools/libxl/xl_cmdimpl.c | 57 ++++++++++++++++++++++++++++++++-- xen/arch/x86/hvm/hvm.c | 18 ++++++++++- xen/arch/x86/hvm/viridian.c | 21 +++++++++++-- xen/include/asm-x86/hvm/hvm.h | 7 +++-- xen/include/public/hvm/params.h | 33 +++++++++++++++++++- 12 files changed, 266 insertions(+), 26 deletions(-) diff --git a/docs/man/xl.cfg.pod.5 b/docs/man/xl.cfg.pod.5 index 1e04eed..4090464 100644 --- a/docs/man/xl.cfg.pod.5 +++ b/docs/man/xl.cfg.pod.5 @@ -1106,18 +1106,59 @@ Windows L<http://wiki.xen.org/wiki/XenWindowsGplPv>. 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=[ "SET", "SET", ...]> + +The sets of Microsoft Hyper-V (AKA viridian) compatible enlightenments +exposed to the guest. The following sets of enlightenments may be +specified: + +=over 4 + +=item B<base> + +This set 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 set is also a pre-requisite for all other sets. If it is +disabled then all enlightenments will be disabled. + +=item B<freq> + +This set incorporates the TSC and APIC frequency MSRs. + +These enlightenments can improve performance of Windows 7 and Windows +Server 2008 R2 onwards. + +=item B<all> + +This is a special value that enables all of the above sets + +=back + +Sets can be disabled by prefixing the name with '!'. So, for example, +to enable all sets 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. + +Specifying the viridian option as a boolean is deprecated. However, for +backwards compatibility, if it is specified as a boolean a value of +true (1) will cause both the B<base> and B<freq> sets to be exposed to +the guest, and a value of false (0) will disable all enlightenments. =back diff --git a/tools/libxc/xc_domain_restore.c b/tools/libxc/xc_domain_restore.c index b9a56d5..d362e3a 100644 --- a/tools/libxc/xc_domain_restore.c +++ b/tools/libxc/xc_domain_restore.c @@ -922,7 +922,7 @@ static int pagebuf_get_one(xc_interface *xch, struct restore_ctx *ctx, 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); @@ -1733,7 +1733,7 @@ int xc_domain_restore(xc_interface *xch, int io_fd, uint32_t 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 diff --git a/tools/libxl/gentypes.py b/tools/libxl/gentypes.py index 3e73821..e101de4 100644 --- a/tools/libxl/gentypes.py +++ b/tools/libxl/gentypes.py @@ -564,6 +564,8 @@ if __name__ == '__main__': f.write("%sconst char *%s_to_string(%s);\n" % (ty.hidden(), ty.typename, ty.make_arg("p"))) f.write("%sint %s_from_string(const char *s, %s);\n" % (ty.hidden(), ty.typename, ty.make_arg("e", passby=idl.PASS_BY_REFERENCE))) f.write("%sextern libxl_enum_string_table %s_string_table[];\n" % (ty.hidden(), ty.typename)) + f.write("%sextern %s %s_min_val;\n" % (ty.hidden(), ty.typename, ty.typename)) + f.write("%sextern %s %s_max_val;\n" % (ty.hidden(), ty.typename, ty.typename)) f.write("\n") f.write("""#endif /* %s */\n""" % (header_define)) @@ -678,6 +680,10 @@ if __name__ == '__main__': f.write("}\n") f.write("\n") + f.write("%s %s_min_val = %d;\n" % (ty.typename, ty.typename, ty.min)) + f.write("%s %s_max_val = %d;\n" % (ty.typename, ty.typename, ty.max)) + f.write("\n") + for ty in [t for t in types if t.json_gen_fn is not None]: f.write("yajl_gen_status %s_gen_json(yajl_gen hand, %s)\n" % (ty.typename, ty.make_arg("p", passby=idl.PASS_BY_REFERENCE))) f.write("{\n") diff --git a/tools/libxl/idl.py b/tools/libxl/idl.py index 437049e..983253d 100644 --- a/tools/libxl/idl.py +++ b/tools/libxl/idl.py @@ -174,9 +174,15 @@ class Enumeration(Type): self.namespace) self.values = [] + self.min = sys.maxint + self.max = -sys.maxint - 1 for v in values: # (value, name) (num,name) = v + if num < self.min: + self.min = num + if num > self.max: + self.max = num self.values.append(EnumerationValue(self, num, name, typename=self.rawname)) def lookup(self, name): diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h index bfeb3bc..6f628cf 100644 --- a/tools/libxl/libxl.h +++ b/tools/libxl/libxl.h @@ -128,6 +128,11 @@ #define LIBXL_HAVE_LIBXL_DEVICE_DISK_DISCARD_ENABLE 1 /* + * libxl_domain_build_info has u.hvm.viridian_enable and _disable fields. + */ +#define LIBXL_HAVE_BUILDINFO_HVM_VIRIDIAN_ENABLE_DISABLE 1 + +/* * libxl ABI compatibility * * The only guarantee which libxl makes regarding ABI compatibility diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c index c944804..d8dfbad 100644 --- a/tools/libxl/libxl_dom.c +++ b/tools/libxl/libxl_dom.c @@ -209,14 +209,66 @@ static unsigned long timer_mode(const libxl_domain_build_info *info) return ((unsigned long)mode); } +#if defined(__i386__) || defined(__x86_64__) +static void 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; + + if (!libxl_defbool_val(info->u.hvm.viridian)) + return; + + libxl_bitmap_init(&enlightenments); + libxl_bitmap_alloc(CTX, &enlightenments, libxl_viridian_enlightenment_max_val); + + if (libxl_bitmap_is_empty(&info->u.hvm.viridian_enable) && + libxl_bitmap_is_empty(&info->u.hvm.viridian_disable)) { + /* Use historical defaults */ + libxl_bitmap_set(&enlightenments, LIBXL_VIRIDIAN_ENLIGHTENMENT_BASE); + libxl_bitmap_set(&enlightenments, LIBXL_VIRIDIAN_ENLIGHTENMENT_FREQ); + } else { + libxl_for_each_set_bit(v, info->u.hvm.viridian_enable) + if (v <= libxl_viridian_enlightenment_max_val && + !libxl_bitmap_test(&info->u.hvm.viridian_disable, v)) + libxl_bitmap_set(&enlightenments, v); + + /* The base set is a pre-requisite for all others */ + if (!libxl_bitmap_test(&enlightenments, LIBXL_VIRIDIAN_ENLIGHTENMENT_BASE)) { + LOG(DETAIL, "base set not enabled"); + libxl_bitmap_set_none(&enlightenments); + } + } + + libxl_for_each_set_bit(v, enlightenments) + LOG(DETAIL, "%s set 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 (xc_hvm_param_set(CTX->xch, + domid, + HVM_PARAM_VIRIDIAN, + mask) != 0) + LIBXL__LOG_ERRNO(CTX, LIBXL__LOG_WARNING, + "Couldn't set viridian feature mask (0x%"PRIx64")", + mask); + + libxl_bitmap_dispose(&enlightenments); +} +#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 @@ -350,8 +402,12 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid, 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__) + hvm_set_viridian_features(gc, domid, info); +#endif + } rc = libxl__arch_domain_create(gc, d_config, domid); diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl index 0b3496f..f383ce0 100644 --- a/tools/libxl/libxl_types.idl +++ b/tools/libxl/libxl_types.idl @@ -175,6 +175,12 @@ libxl_vendor_device = Enumeration("vendor_device", [ (0, "NONE"), (1, "XENSERVER"), ]) + +libxl_viridian_enlightenment = Enumeration("viridian_enlightenment", [ + (0, "base"), + (1, "freq"), + ]) + # # Complex libxl types # @@ -365,6 +371,8 @@ libxl_domain_build_info = Struct("domain_build_info",[ ("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), diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c index f1c136a..9ca88ce 100644 --- a/tools/libxl/xl_cmdimpl.c +++ b/tools/libxl/xl_cmdimpl.c @@ -775,8 +775,8 @@ static void parse_config_data(const char *config_source, 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; @@ -993,10 +993,61 @@ static void parse_config_data(const char *config_source, 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_defbool_set(&b_info->u.hvm.viridian, true); + + libxl_bitmap_alloc(ctx, &b_info->u.hvm.viridian_enable, + libxl_viridian_enlightenment_max_val + 1); + libxl_bitmap_alloc(ctx, &b_info->u.hvm.viridian_disable, + libxl_viridian_enlightenment_max_val + 1); + } + 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 { + libxl_bitmap *m = &b_info->u.hvm.viridian_enable; + + if (*buf == '!') { + m = &b_info->u.hvm.viridian_disable; + 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(m, v); + } + } + break; + case ESRCH: break; /* Option not present */ + case EINVAL: + xlu_cfg_get_defbool(config, "viridian", &b_info->u.hvm.viridian, 1); + if (libxl_defbool_val(b_info->u.hvm.viridian)) { + fprintf(stderr, "WARNING: Specifying \"viridian\"" + " as a boolean is deprecated. " + "Please use a list of features.\n"); + } + 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. " diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 94b18ba..8aeb8a6 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -5554,8 +5554,24 @@ long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) arg) 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(). */ diff --git a/xen/arch/x86/hvm/viridian.c b/xen/arch/x86/hvm/viridian.c index b646a8a..28c4479 100644 --- a/xen/arch/x86/hvm/viridian.c +++ b/xen/arch/x86/hvm/viridian.c @@ -90,8 +90,9 @@ int cpuid_viridian_leaves(unsigned int leaf, unsigned int *eax, /* 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. */ @@ -312,11 +313,17 @@ int rdmsr_viridian_regs(uint32_t idx, uint64_t *val) 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; @@ -489,3 +496,13 @@ static int viridian_load_vcpu_ctxt(struct domain *d, hvm_domain_context_t *h) 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: + */ diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h index 0ebd478..24e513b 100644 --- a/xen/include/asm-x86/hvm/hvm.h +++ b/xen/include/asm-x86/hvm/hvm.h @@ -344,8 +344,11 @@ static inline unsigned long hvm_get_shadow_gs_base(struct vcpu *v) 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, diff --git a/xen/include/public/hvm/params.h b/xen/include/public/hvm/params.h index 614ff5f..68d26fd 100644 --- a/xen/include/public/hvm/params.h +++ b/xen/include/public/hvm/params.h @@ -56,9 +56,40 @@ #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 /* -- 1.7.10.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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