From: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx> Sent: Wednesday, February 19, 2025 3:53 PM > > On 2/19/2025 11:46 AM, Michael Kelley wrote: > > From: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx> Sent: Tuesday, > February 11, 2025 2:22 PM > >> > >> Introduce CONFIG_MSHV_ROOT as a tristate to enable root partition > >> booting and future mshv driver functionality. > > > > This statement could use a bit more explanation as to "why". Something > > like: > > > > Running in the root partition is a unique and specialized case that requires > > additional code. The config option allows kernels built to run as a normal > > Hyper-V guest to exclude this code, which is important since significant > > additional code specific to the root partition is expected to be added over > > time. > > > > This sounds good to me > > > Related, what's the thinking behind making CONFIG_MSHV_ROOT be > > tri-state? Obviously, it would allow most of the root partition code > > to be loaded as a module instead of built-in to the kernel image, but is that > > a useful scenario given the unique nature of running in the root partition? > > Since the root partition environment is very specific and constrained, > > perhaps just always building the root partition code into the kernel > > makes sense. I'm asking purely as a question because I'm not familiar with > > the details of how a root partition kernel is likely to be setup & run. If > > possible, give a short explanation for the "why tri-state" question. > > Remember, that's what commit message are for -- to answer the "why" > > question as much as to summarize the "what" question. > > > > In the past it enabled quicker development: I would iterate on the driver > code and just rebuild and reinsert the module. I'll admit I haven't used that > workflow in a while so I'm not sure how useful it still is. > > Is there a *downside* (from upstream perspective) to keeping it a tristate > that I'm not aware of? e.g. Would it be difficult to change it to a bool in > future if we decide we really don't need it? OK -- I had not thought about the development workflow, and that's valid. There's no downside to keeping it tri-state that I'm aware of. And I think it would be easy to change to just a Boolean in the future if tri-state isn't really useful. It was just one of those things that surprised me a little bit, and I was wondering "why". :-) > > While we're on this topic, do you know if CONFIG_HYPERV=m is ever used, and > why? Yes, it is definitely used by the distro vendors. They want to have a single product release that is useable pretty much everywhere. So they don't want to burden the main kernel binary with Hyper-V code that wouldn't be used on bare metal, or a KVM/QEMU VM, etc. Azure images might be a little more specific to Hyper-V, and might have the Hyper-V code built-in -- it depends on the distro vendor. I don't remember having taken a census to know which approach predominates, but my guess is "=m". > > >> > >> Change hv_root_partition into a function which always returns false > >> if CONFIG_MSHV_ROOT=n. > > > > Again, help answer the "why" question. I think the goal is related to > > the above by allowing the compiler to optimize away any "if (root partition)" > > code when building for a normal Hyper-V guest. > > > >> > >> Introduce hv_current_partition_type to store the type of partition > >> (guest, root, or other kinds in future), and hv_identify_partition_type() > >> to it up early in Hyper-V initialization. > >> > >> Signed-off-by: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx> > >> --- > >> Depends on > >> https://lore.kernel.org/linux-hyperv/1738955002-20821-3-git-send-email-nunodasneves@xxxxxxxxxxxxxxxxxxx/ > >> > >> arch/arm64/hyperv/mshyperv.c | 2 ++ > >> arch/x86/hyperv/hv_init.c | 10 ++++---- > >> arch/x86/kernel/cpu/mshyperv.c | 24 ++---------------- > >> drivers/clocksource/hyperv_timer.c | 4 +-- > >> drivers/hv/Kconfig | 12 +++++++++ > >> drivers/hv/Makefile | 3 ++- > >> drivers/hv/hv.c | 10 ++++---- > >> drivers/hv/hv_common.c | 32 +++++++++++++++++++----- > >> drivers/hv/vmbus_drv.c | 2 +- > >> drivers/iommu/hyperv-iommu.c | 4 +-- > >> include/asm-generic/mshyperv.h | 39 +++++++++++++++++++++++++----- > >> 11 files changed, 92 insertions(+), 50 deletions(-) > >> > >> diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c > >> index 29fcfd595f48..2265ea5ce5ad 100644 > >> --- a/arch/arm64/hyperv/mshyperv.c > >> +++ b/arch/arm64/hyperv/mshyperv.c > >> @@ -61,6 +61,8 @@ static int __init hyperv_init(void) > >> ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints, > >> ms_hyperv.misc_features); > >> > >> + hv_identify_partition_type(); > >> + > >> ret = hv_common_init(); > >> if (ret) > >> return ret; > >> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c > >> index 9be1446f5bd3..ddeb40930bc8 100644 > >> --- a/arch/x86/hyperv/hv_init.c > >> +++ b/arch/x86/hyperv/hv_init.c > >> @@ -90,7 +90,7 @@ static int hv_cpu_init(unsigned int cpu) > >> return 0; > >> > >> hvp = &hv_vp_assist_page[cpu]; > >> - if (hv_root_partition) { > >> + if (hv_root_partition()) { > >> /* > >> * For root partition we get the hypervisor provided VP assist > >> * page, instead of allocating a new page. > >> @@ -242,7 +242,7 @@ static int hv_cpu_die(unsigned int cpu) > >> > >> if (hv_vp_assist_page && hv_vp_assist_page[cpu]) { > >> union hv_vp_assist_msr_contents msr = { 0 }; > >> - if (hv_root_partition) { > >> + if (hv_root_partition()) { > >> /* > >> * For root partition the VP assist page is mapped to > >> * hypervisor provided page, and thus we unmap the > >> @@ -317,7 +317,7 @@ static int hv_suspend(void) > >> union hv_x64_msr_hypercall_contents hypercall_msr; > >> int ret; > >> > >> - if (hv_root_partition) > >> + if (hv_root_partition()) > >> return -EPERM; > >> > >> /* > >> @@ -518,7 +518,7 @@ void __init hyperv_init(void) > >> rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); > >> hypercall_msr.enable = 1; > >> > >> - if (hv_root_partition) { > >> + if (hv_root_partition()) { > >> struct page *pg; > >> void *src; > >> > >> @@ -592,7 +592,7 @@ void __init hyperv_init(void) > >> * If we're running as root, we want to create our own PCI MSI domain. > >> * We can't set this in hv_pci_init because that would be too late. > >> */ > >> - if (hv_root_partition) > >> + if (hv_root_partition()) > >> x86_init.irqs.create_pci_msi_domain = hv_create_pci_msi_domain; > >> #endif > >> > >> diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c > >> index f285757618fc..4f01f424ea5b 100644 > >> --- a/arch/x86/kernel/cpu/mshyperv.c > >> +++ b/arch/x86/kernel/cpu/mshyperv.c > >> @@ -33,8 +33,6 @@ > >> #include <asm/numa.h> > >> #include <asm/svm.h> > >> > >> -/* Is Linux running as the root partition? */ > >> -bool hv_root_partition; > >> /* Is Linux running on nested Microsoft Hypervisor */ > >> bool hv_nested; > >> struct ms_hyperv_info ms_hyperv; > >> @@ -451,25 +449,7 @@ static void __init ms_hyperv_init_platform(void) > >> pr_debug("Hyper-V: max %u virtual processors, %u logical processors\n", > >> ms_hyperv.max_vp_index, ms_hyperv.max_lp_index); > >> > >> - /* > >> - * Check CPU management privilege. > >> - * > >> - * To mirror what Windows does we should extract CPU management > >> - * features and use the ReservedIdentityBit to detect if Linux is the > >> - * root partition. But that requires negotiating CPU management > >> - * interface (a process to be finalized). For now, use the privilege > >> - * flag as the indicator for running as root. > >> - * > >> - * Hyper-V should never specify running as root and as a Confidential > >> - * VM. But to protect against a compromised/malicious Hyper-V trying > >> - * to exploit root behavior to expose Confidential VM memory, ignore > >> - * the root partition setting if also a Confidential VM. > >> - */ > >> - if ((ms_hyperv.priv_high & HV_CPU_MANAGEMENT) && > >> - !(ms_hyperv.priv_high & HV_ISOLATION)) { > >> - hv_root_partition = true; > >> - pr_info("Hyper-V: running as root partition\n"); > >> - } > >> + hv_identify_partition_type(); > >> > >> if (ms_hyperv.hints & HV_X64_HYPERV_NESTED) { > >> hv_nested = true; > >> @@ -618,7 +598,7 @@ static void __init ms_hyperv_init_platform(void) > >> > >> # ifdef CONFIG_SMP > >> smp_ops.smp_prepare_boot_cpu = hv_smp_prepare_boot_cpu; > >> - if (hv_root_partition || > >> + if (hv_root_partition() || > >> (!ms_hyperv.paravisor_present && hv_isolation_type_snp())) > >> smp_ops.smp_prepare_cpus = hv_smp_prepare_cpus; > >> # endif > >> diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c > >> index f00019b078a7..09549451dd51 100644 > >> --- a/drivers/clocksource/hyperv_timer.c > >> +++ b/drivers/clocksource/hyperv_timer.c > >> @@ -582,7 +582,7 @@ static void __init hv_init_tsc_clocksource(void) > >> * mapped. > >> */ > >> tsc_msr.as_uint64 = hv_get_msr(HV_MSR_REFERENCE_TSC); > >> - if (hv_root_partition) > >> + if (hv_root_partition()) > >> tsc_pfn = tsc_msr.pfn; > >> else > >> tsc_pfn = HVPFN_DOWN(virt_to_phys(tsc_page)); > >> @@ -627,7 +627,7 @@ void __init hv_remap_tsc_clocksource(void) > >> if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) > >> return; > >> > >> - if (!hv_root_partition) { > >> + if (!hv_root_partition()) { > >> WARN(1, "%s: attempt to remap TSC page in guest partition\n", > >> __func__); > >> return; > >> diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig > >> index 862c47b191af..aac172942f6c 100644 > >> --- a/drivers/hv/Kconfig > >> +++ b/drivers/hv/Kconfig > >> @@ -55,4 +55,16 @@ config HYPERV_BALLOON > >> help > >> Select this option to enable Hyper-V Balloon driver. > >> > >> +config MSHV_ROOT > >> + tristate "Microsoft Hyper-V root partition support" > >> + depends on HYPERV > >> + depends on !HYPERV_VTL_MODE > >> + depends on PAGE_SIZE_4KB > > > > Add a comment about why PAGE_SIZE_4KB is a requirement, even on > > arm64 systems that can support guests with larger page sizes. We > > discussed why in an earlier email thread, but somebody looking at > > this in the future might wonder. > > > >> + default n > >> + help > >> + Select this option to enable support for booting and running as root > >> + partition on Microsoft Hyper-V. > >> + > >> + If unsure, say N. > >> + > > > > One thing to keep in mind: Sometimes people build kernels with all > > config options set to "Y". We want to make sure that if someone does > > that, the kernel will still run in a non-Hyper-V environment. We had this > > problem with CONFIG_HYPERV_VTL_MODE=y, where a kernel built with > > that wouldn't run elsewhere, and that had to be fixed. I don't think the > > changes in this patch cause a problem in that regard, but it is something > > to keep in mind for the future. > > > > As I see it, setting CONFIG_MSHV_ROOT=y (or =m) just adds code to > > the kernel image or modules list, and enables runtime detection of > > whether the kernel is actually in the root partition. If not actually in the > > root partition, the behavior is normal guest behavior. I think that is all good. > > > Yes, agreed. The assumption we are working under is that enabling > CONFIG_MSHV_ROOT > doesn't break any normal guest or non-Hyper-V scenarios. > > Of course it's hard to always be certain that our code doesn't break some other > config option at runtime, but we fix that whenever we see it (or exclude the > combination via Kconfig). > > >> endmenu > >> diff --git a/drivers/hv/Makefile b/drivers/hv/Makefile > >> index 9afcabb3fbd2..2b8dc954b350 100644 > >> --- a/drivers/hv/Makefile > >> +++ b/drivers/hv/Makefile > >> @@ -13,4 +13,5 @@ hv_vmbus-$(CONFIG_HYPERV_TESTING) += hv_debugfs.o > >> hv_utils-y := hv_util.o hv_kvp.o hv_snapshot.o hv_utils_transport.o > >> > >> # Code that must be built-in > >> -obj-$(subst m,y,$(CONFIG_HYPERV)) += hv_common.o hv_proc.o > >> +obj-$(subst m,y,$(CONFIG_HYPERV)) += hv_common.o > >> +obj-$(subst m,y,$(CONFIG_MSHV_ROOT)) += hv_proc.o > > > > OK, so hv_proc.o is always built-in, regardless of whether > > CONFIG_MSHV_ROOT=y or =m. I think that makes sense. The functions in > > hv_proc.c are called somewhere in the middle of the kernel boot process, > > and I'm unsure if the module loading mechanism is fully set up at the point > > the functions are needed. This approach avoids any risk of not being able > > to load the module. Presumably still-to-be-added code for the root partition > > could be built as a module (though see my comment in the commit message). > > > > Yep, that was the idea. > > >> diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c > >> index 36d9ba097ff5..93d82382351c 100644 > >> --- a/drivers/hv/hv.c > >> +++ b/drivers/hv/hv.c > >> @@ -144,7 +144,7 @@ int hv_synic_alloc(void) > >> * Synic message and event pages are allocated by paravisor. > >> * Skip these pages allocation here. > >> */ > >> - if (!ms_hyperv.paravisor_present && !hv_root_partition) { > >> + if (!ms_hyperv.paravisor_present && !hv_root_partition()) { > >> hv_cpu->synic_message_page = > >> (void *)get_zeroed_page(GFP_ATOMIC); > >> if (!hv_cpu->synic_message_page) { > >> @@ -272,7 +272,7 @@ void hv_synic_enable_regs(unsigned int cpu) > >> simp.as_uint64 = hv_get_msr(HV_MSR_SIMP); > >> simp.simp_enabled = 1; > >> > >> - if (ms_hyperv.paravisor_present || hv_root_partition) { > >> + if (ms_hyperv.paravisor_present || hv_root_partition()) { > >> /* Mask out vTOM bit. ioremap_cache() maps decrypted */ > >> u64 base = (simp.base_simp_gpa << HV_HYP_PAGE_SHIFT) & > >> ~ms_hyperv.shared_gpa_boundary; > >> @@ -291,7 +291,7 @@ void hv_synic_enable_regs(unsigned int cpu) > >> siefp.as_uint64 = hv_get_msr(HV_MSR_SIEFP); > >> siefp.siefp_enabled = 1; > >> > >> - if (ms_hyperv.paravisor_present || hv_root_partition) { > >> + if (ms_hyperv.paravisor_present || hv_root_partition()) { > >> /* Mask out vTOM bit. ioremap_cache() maps decrypted */ > >> u64 base = (siefp.base_siefp_gpa << HV_HYP_PAGE_SHIFT) & > >> ~ms_hyperv.shared_gpa_boundary; > >> @@ -367,7 +367,7 @@ void hv_synic_disable_regs(unsigned int cpu) > >> * addresses. > >> */ > >> simp.simp_enabled = 0; > >> - if (ms_hyperv.paravisor_present || hv_root_partition) { > >> + if (ms_hyperv.paravisor_present || hv_root_partition()) { > >> iounmap(hv_cpu->synic_message_page); > >> hv_cpu->synic_message_page = NULL; > >> } else { > >> @@ -379,7 +379,7 @@ void hv_synic_disable_regs(unsigned int cpu) > >> siefp.as_uint64 = hv_get_msr(HV_MSR_SIEFP); > >> siefp.siefp_enabled = 0; > >> > >> - if (ms_hyperv.paravisor_present || hv_root_partition) { > >> + if (ms_hyperv.paravisor_present || hv_root_partition()) { > >> iounmap(hv_cpu->synic_event_page); > >> hv_cpu->synic_event_page = NULL; > >> } else { > >> diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c > >> index cb3ea49020ef..d1227e85c5b7 100644 > >> --- a/drivers/hv/hv_common.c > >> +++ b/drivers/hv/hv_common.c > >> @@ -34,8 +34,11 @@ > >> u64 hv_current_partition_id = HV_PARTITION_ID_SELF; > >> EXPORT_SYMBOL_GPL(hv_current_partition_id); > >> > >> +enum hv_partition_type hv_current_partition_type; > >> +EXPORT_SYMBOL_GPL(hv_current_partition_type); > >> + > >> /* > >> - * hv_root_partition, ms_hyperv and hv_nested are defined here with other > >> + * ms_hyperv and hv_nested are defined here with other > >> * Hyper-V specific globals so they are shared across all architectures and are > >> * built only when CONFIG_HYPERV is defined. But on x86, > >> * ms_hyperv_init_platform() is built even when CONFIG_HYPERV is not > >> @@ -43,9 +46,6 @@ EXPORT_SYMBOL_GPL(hv_current_partition_id); > >> * here, allowing for an overriding definition in the module containing > >> * ms_hyperv_init_platform(). > >> */ > >> -bool __weak hv_root_partition; > >> -EXPORT_SYMBOL_GPL(hv_root_partition); > >> - > >> bool __weak hv_nested; > >> EXPORT_SYMBOL_GPL(hv_nested); > >> > >> @@ -283,7 +283,7 @@ static void hv_kmsg_dump_register(void) > >> > >> static inline bool hv_output_page_exists(void) > >> { > >> - return hv_root_partition || IS_ENABLED(CONFIG_HYPERV_VTL_MODE); > >> + return hv_root_partition() || IS_ENABLED(CONFIG_HYPERV_VTL_MODE); > >> } > >> > >> void __init hv_get_partition_id(void) > >> @@ -594,7 +594,7 @@ EXPORT_SYMBOL_GPL(hv_setup_dma_ops); > >> > >> bool hv_is_hibernation_supported(void) > >> { > >> - return !hv_root_partition && acpi_sleep_state_supported(ACPI_STATE_S4); > >> + return !hv_root_partition() && acpi_sleep_state_supported(ACPI_STATE_S4); > >> } > >> EXPORT_SYMBOL_GPL(hv_is_hibernation_supported); > >> > >> @@ -683,3 +683,23 @@ u64 __weak hv_tdx_hypercall(u64 control, u64 param1, u64 param2) > >> return HV_STATUS_INVALID_PARAMETER; > >> } > >> EXPORT_SYMBOL_GPL(hv_tdx_hypercall); > >> + > >> +void hv_identify_partition_type(void) > >> +{ > >> + /* > >> + * Check partition creation and cpu management privileges > >> + * > >> + * Hyper-V should never specify running as root and as a Confidential > >> + * VM. But to protect against a compromised/malicious Hyper-V trying > >> + * to exploit root behavior to expose Confidential VM memory, ignore > >> + * the root partition setting if also a Confidential VM. > >> + */ > >> + if ((ms_hyperv.priv_high & HV_CREATE_PARTITIONS) && > >> + (ms_hyperv.priv_high & HV_CPU_MANAGEMENT) && > >> + !(ms_hyperv.priv_high & HV_ISOLATION)) { > >> + hv_current_partition_type = HV_PARTITION_TYPE_ROOT; > >> + pr_info("Hyper-V: running as root partition\n"); > >> + } else { > >> + hv_current_partition_type = HV_PARTITION_TYPE_GUEST; > >> + } > > > > If the flags indicate running in the root partition, but CONFIG_MSHV_ROOT=n, > > perhaps that should probably be flagged with an error message. I haven't thought > > through what to do then: Panic, keep running as a normal guest, or something else? > > > > If the kernel is run as root partition with CONFIG_MSHV_ROOT=n, I think it will crash > or hang at some point later in boot. > > How about this: > > if ((ms_hyperv.priv_high & HV_CREATE_PARTITIONS) && > (ms_hyperv.priv_high & HV_CPU_MANAGEMENT) && > !(ms_hyperv.priv_high & HV_ISOLATION)) { > pr_info("Hyper-V: running as root partition\n"); > if (IS_ENABLED(CONFIG_MSHV_ROOT)) > hv_current_partition_type = HV_PARTITION_TYPE_ROOT; > else > pr_crit("Hyper-V: CONFIG_MSHV_ROOT not enabled!\n"); > } > > We could also BUG_ON() since it will almost certainly crash anyway, but maybe just > letting it continue is ok. I'm OK with just continuing, as I don't have any justification for an alternative. It's a strange situation that should not happen, but it's worthwhile to output some indication of why things are about to go badly. Michael > > >> +} > >> diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c > >> index 0f6cd44fff29..844eba0429fa 100644 > >> --- a/drivers/hv/vmbus_drv.c > >> +++ b/drivers/hv/vmbus_drv.c > >> @@ -2646,7 +2646,7 @@ static int __init hv_acpi_init(void) > >> if (!hv_is_hyperv_initialized()) > >> return -ENODEV; > >> > >> - if (hv_root_partition && !hv_nested) > >> + if (hv_root_partition() && !hv_nested) > >> return 0; > >> > >> /* > >> diff --git a/drivers/iommu/hyperv-iommu.c b/drivers/iommu/hyperv-iommu.c > >> index 2a86aa5d54c6..53e4b37716af 100644 > >> --- a/drivers/iommu/hyperv-iommu.c > >> +++ b/drivers/iommu/hyperv-iommu.c > >> @@ -130,7 +130,7 @@ static int __init hyperv_prepare_irq_remapping(void) > >> x86_init.hyper.msi_ext_dest_id()) > >> return -ENODEV; > >> > >> - if (hv_root_partition) { > >> + if (hv_root_partition()) { > >> name = "HYPERV-ROOT-IR"; > >> ops = &hyperv_root_ir_domain_ops; > >> } else { > >> @@ -151,7 +151,7 @@ static int __init hyperv_prepare_irq_remapping(void) > >> return -ENOMEM; > >> } > >> > >> - if (hv_root_partition) > >> + if (hv_root_partition()) > >> return 0; /* The rest is only relevant to guests */ > >> > >> /* > >> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h > >> index 7adc10a4fa3e..6f898792fb51 100644 > >> --- a/include/asm-generic/mshyperv.h > >> +++ b/include/asm-generic/mshyperv.h > >> @@ -28,6 +28,11 @@ > >> > >> #define VTPM_BASE_ADDRESS 0xfed40000 > >> > >> +enum hv_partition_type { > >> + HV_PARTITION_TYPE_GUEST, > >> + HV_PARTITION_TYPE_ROOT, > >> +}; > >> + > >> struct ms_hyperv_info { > >> u32 features; > >> u32 priv_high; > >> @@ -59,6 +64,7 @@ struct ms_hyperv_info { > >> extern struct ms_hyperv_info ms_hyperv; > >> extern bool hv_nested; > >> extern u64 hv_current_partition_id; > >> +extern enum hv_partition_type hv_current_partition_type; > >> > >> extern void * __percpu *hyperv_pcpu_input_arg; > >> extern void * __percpu *hyperv_pcpu_output_arg; > >> @@ -190,8 +196,6 @@ void hv_remove_crash_handler(void); > >> extern int vmbus_interrupt; > >> extern int vmbus_irq; > >> > >> -extern bool hv_root_partition; > >> - > >> #if IS_ENABLED(CONFIG_HYPERV) > >> /* > >> * Hypervisor's notion of virtual processor ID is different from > >> @@ -213,15 +217,12 @@ void __init hv_common_free(void); > >> void __init ms_hyperv_late_init(void); > >> int hv_common_cpu_init(unsigned int cpu); > >> int hv_common_cpu_die(unsigned int cpu); > >> +void hv_identify_partition_type(void); > >> > >> void *hv_alloc_hyperv_page(void); > >> void *hv_alloc_hyperv_zeroed_page(void); > >> void hv_free_hyperv_page(void *addr); > >> > >> -int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages); > >> -int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id); > >> -int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags); > >> - > >> /** > >> * hv_cpu_number_to_vp_number() - Map CPU to VP. > >> * @cpu_number: CPU number in Linux terms > >> @@ -309,6 +310,7 @@ void hyperv_cleanup(void); > >> bool hv_query_ext_cap(u64 cap_query); > >> void hv_setup_dma_ops(struct device *dev, bool coherent); > >> #else /* CONFIG_HYPERV */ > >> +static inline void hv_identify_partition_type(void) {} > >> static inline bool hv_is_hyperv_initialized(void) { return false; } > >> static inline bool hv_is_hibernation_supported(void) { return false; } > >> static inline void hyperv_cleanup(void) {} > >> @@ -320,4 +322,29 @@ static inline enum hv_isolation_type hv_get_isolation_type(void) > >> } > >> #endif /* CONFIG_HYPERV */ > >> > >> +#if IS_ENABLED(CONFIG_MSHV_ROOT) > >> +static inline bool hv_root_partition(void) > >> +{ > >> + return hv_current_partition_type == HV_PARTITION_TYPE_ROOT; > > > > Nit: There's an extra space character after "return". > > > > Fixed for next version, thanks. > > >> +} > >> +int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages); > >> +int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id); > >> +int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags); > >> + > >> +#else /* CONFIG_MSHV_ROOT */ > >> +static inline bool hv_root_partition(void) { return false; } > >> +static inline int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages) > >> +{ > >> + return hv_result(U64_MAX); > >> +} > >> +static inline int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id) > >> +{ > >> + return hv_result(U64_MAX); > >> +} > >> +static inline int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags) > >> +{ > >> + return hv_result(U64_MAX); > >> +} > >> +#endif /* CONFIG_MSHV_ROOT */ > >> + > >> #endif > >> -- > >> 2.34.1
