Move the logic to initialize and export hv_vp_assist_page from x86 architecture code to Hyper-V common code to allow it to be used for upcoming arm64 support in MSHV_VTL driver. Note: This change also improves error handling - if VP assist page allocation fails, hyperv_init() now returns early instead of continuing with partial initialization.
Signed-off-by: Roman Kisel <[email protected]> Signed-off-by: Naman Jain <[email protected]> --- arch/x86/hyperv/hv_init.c | 88 +--------------------------------- drivers/hv/hv_common.c | 88 ++++++++++++++++++++++++++++++++++ include/asm-generic/mshyperv.h | 4 ++ include/hyperv/hvgdk_mini.h | 2 + 4 files changed, 95 insertions(+), 87 deletions(-) diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index 323adc93f2dc..75a98b5e451b 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -81,9 +81,6 @@ union hv_ghcb * __percpu *hv_ghcb_pg; /* Storage to save the hypercall page temporarily for hibernation */ static void *hv_hypercall_pg_saved; -struct hv_vp_assist_page **hv_vp_assist_page; -EXPORT_SYMBOL_GPL(hv_vp_assist_page); - static int hyperv_init_ghcb(void) { u64 ghcb_gpa; @@ -117,59 +114,12 @@ static int hyperv_init_ghcb(void) static int hv_cpu_init(unsigned int cpu) { - union hv_vp_assist_msr_contents msr = { 0 }; - struct hv_vp_assist_page **hvp; int ret; ret = hv_common_cpu_init(cpu); if (ret) return ret; - if (!hv_vp_assist_page) - return 0; - - hvp = &hv_vp_assist_page[cpu]; - if (hv_root_partition()) { - /* - * For root partition we get the hypervisor provided VP assist - * page, instead of allocating a new page. - */ - rdmsrq(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64); - *hvp = memremap(msr.pfn << HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT, - PAGE_SIZE, MEMREMAP_WB); - } else { - /* - * The VP assist page is an "overlay" page (see Hyper-V TLFS's - * Section 5.2.1 "GPA Overlay Pages"). Here it must be zeroed - * out to make sure we always write the EOI MSR in - * hv_apic_eoi_write() *after* the EOI optimization is disabled - * in hv_cpu_die(), otherwise a CPU may not be stopped in the - * case of CPU offlining and the VM will hang. - */ - if (!*hvp) { - *hvp = __vmalloc(PAGE_SIZE, GFP_KERNEL | __GFP_ZERO); - - /* - * Hyper-V should never specify a VM that is a Confidential - * VM and also running in the root partition. Root partition - * is blocked to run in Confidential VM. So only decrypt assist - * page in non-root partition here. - */ - if (*hvp && !ms_hyperv.paravisor_present && hv_isolation_type_snp()) { - WARN_ON_ONCE(set_memory_decrypted((unsigned long)(*hvp), 1)); - memset(*hvp, 0, PAGE_SIZE); - } - } - - if (*hvp) - msr.pfn = vmalloc_to_pfn(*hvp); - - } - if (!WARN_ON(!(*hvp))) { - msr.enable = 1; - wrmsrq(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64); - } - /* Allow Hyper-V stimer vector to be injected from Hypervisor. */ if (ms_hyperv.misc_features & HV_STIMER_DIRECT_MODE_AVAILABLE) apic_update_vector(cpu, HYPERV_STIMER0_VECTOR, true); @@ -286,23 +236,6 @@ static int hv_cpu_die(unsigned int cpu) hv_common_cpu_die(cpu); - if (hv_vp_assist_page && hv_vp_assist_page[cpu]) { - union hv_vp_assist_msr_contents msr = { 0 }; - if (hv_root_partition()) { - /* - * For root partition the VP assist page is mapped to - * hypervisor provided page, and thus we unmap the - * page here and nullify it, so that in future we have - * correct page address mapped in hv_cpu_init. - */ - memunmap(hv_vp_assist_page[cpu]); - hv_vp_assist_page[cpu] = NULL; - rdmsrq(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64); - msr.enable = 0; - } - wrmsrq(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64); - } - if (hv_reenlightenment_cb == NULL) return 0; @@ -460,21 +393,6 @@ void __init hyperv_init(void) if (hv_common_init()) return; - /* - * The VP assist page is useless to a TDX guest: the only use we - * would have for it is lazy EOI, which can not be used with TDX. - */ - if (hv_isolation_type_tdx()) - hv_vp_assist_page = NULL; - else - hv_vp_assist_page = kzalloc_objs(*hv_vp_assist_page, nr_cpu_ids); - if (!hv_vp_assist_page) { - ms_hyperv.hints &= ~HV_X64_ENLIGHTENED_VMCS_RECOMMENDED; - - if (!hv_isolation_type_tdx()) - goto common_free; - } - if (ms_hyperv.paravisor_present && hv_isolation_type_snp()) { /* Negotiate GHCB Version. */ if (!hv_ghcb_negotiate_protocol()) @@ -483,7 +401,7 @@ void __init hyperv_init(void) hv_ghcb_pg = alloc_percpu(union hv_ghcb *); if (!hv_ghcb_pg) - goto free_vp_assist_page; + goto free_ghcb_page; } cpuhp = cpuhp_setup_state(CPUHP_AP_HYPERV_ONLINE, "x86/hyperv_init:online", @@ -613,10 +531,6 @@ void __init hyperv_init(void) cpuhp_remove_state(CPUHP_AP_HYPERV_ONLINE); free_ghcb_page: free_percpu(hv_ghcb_pg); -free_vp_assist_page: - kfree(hv_vp_assist_page); - hv_vp_assist_page = NULL; -common_free: hv_common_free(); } diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c index 6b67ac616789..d1ebc0ebd08f 100644 --- a/drivers/hv/hv_common.c +++ b/drivers/hv/hv_common.c @@ -28,7 +28,9 @@ #include <linux/slab.h> #include <linux/dma-map-ops.h> #include <linux/set_memory.h> +#include <linux/vmalloc.h> #include <hyperv/hvhdk.h> +#include <hyperv/hvgdk.h> #include <asm/mshyperv.h> u64 hv_current_partition_id = HV_PARTITION_ID_SELF; @@ -78,6 +80,8 @@ static struct ctl_table_header *hv_ctl_table_hdr; u8 * __percpu *hv_synic_eventring_tail; EXPORT_SYMBOL_GPL(hv_synic_eventring_tail); +struct hv_vp_assist_page **hv_vp_assist_page; +EXPORT_SYMBOL_GPL(hv_vp_assist_page); /* * Hyper-V specific initialization and shutdown code that is * common across all architectures. Called from architecture @@ -92,6 +96,9 @@ void __init hv_common_free(void) if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) hv_kmsg_dump_unregister(); + kfree(hv_vp_assist_page); + hv_vp_assist_page = NULL; + kfree(hv_vp_index); hv_vp_index = NULL; @@ -394,6 +401,23 @@ int __init hv_common_init(void) for (i = 0; i < nr_cpu_ids; i++) hv_vp_index[i] = VP_INVAL; + /* + * The VP assist page is useless to a TDX guest: the only use we + * would have for it is lazy EOI, which can not be used with TDX. + */ + if (hv_isolation_type_tdx()) { + hv_vp_assist_page = NULL; + } else { + hv_vp_assist_page = kzalloc_objs(*hv_vp_assist_page, nr_cpu_ids); + if (!hv_vp_assist_page) { +#ifdef CONFIG_X86_64 + ms_hyperv.hints &= ~HV_X64_ENLIGHTENED_VMCS_RECOMMENDED; +#endif + hv_common_free(); + return -ENOMEM; + } + } + return 0; } @@ -471,6 +495,8 @@ void __init ms_hyperv_late_init(void) int hv_common_cpu_init(unsigned int cpu) { + union hv_vp_assist_msr_contents msr = { 0 }; + struct hv_vp_assist_page **hvp; void **inputarg, **outputarg; u8 **synic_eventring_tail; u64 msr_vp_index; @@ -542,6 +568,50 @@ int hv_common_cpu_init(unsigned int cpu) ret = -ENOMEM; } + if (!hv_vp_assist_page) + return ret; + + hvp = &hv_vp_assist_page[cpu]; + if (hv_root_partition()) { + /* + * For root partition we get the hypervisor provided VP assist + * page, instead of allocating a new page. + */ + msr.as_uint64 = hv_get_msr(HV_SYN_REG_VP_ASSIST_PAGE); + *hvp = memremap(msr.pfn << HV_VP_ASSIST_PAGE_ADDRESS_SHIFT, + PAGE_SIZE, MEMREMAP_WB); + } else { + /* + * The VP assist page is an "overlay" page (see Hyper-V TLFS's + * Section 5.2.1 "GPA Overlay Pages"). Here it must be zeroed + * out to make sure we always write the EOI MSR in + * hv_apic_eoi_write() *after* the EOI optimization is disabled + * in hv_cpu_die(), otherwise a CPU may not be stopped in the + * case of CPU offlining and the VM will hang. + */ + if (!*hvp) { + *hvp = __vmalloc(PAGE_SIZE, GFP_KERNEL | __GFP_ZERO); + + /* + * Hyper-V should never specify a VM that is a Confidential + * VM and also running in the root partition. Root partition + * is blocked to run in Confidential VM. So only decrypt assist + * page in non-root partition here. + */ + if (*hvp && !ms_hyperv.paravisor_present && hv_isolation_type_snp()) { + WARN_ON_ONCE(set_memory_decrypted((unsigned long)(*hvp), 1)); + memset(*hvp, 0, PAGE_SIZE); + } + } + + if (*hvp) + msr.pfn = vmalloc_to_pfn(*hvp); + } + if (!WARN_ON(!(*hvp))) { + msr.enable = 1; + hv_set_msr(HV_SYN_REG_VP_ASSIST_PAGE, msr.as_uint64); + } + return ret; } @@ -566,6 +636,24 @@ int hv_common_cpu_die(unsigned int cpu) *synic_eventring_tail = NULL; } + if (hv_vp_assist_page && hv_vp_assist_page[cpu]) { + union hv_vp_assist_msr_contents msr = { 0 }; + + if (hv_root_partition()) { + /* + * For root partition the VP assist page is mapped to + * hypervisor provided page, and thus we unmap the + * page here and nullify it, so that in future we have + * correct page address mapped in hv_cpu_init. + */ + memunmap(hv_vp_assist_page[cpu]); + hv_vp_assist_page[cpu] = NULL; + msr.as_uint64 = hv_get_msr(HV_SYN_REG_VP_ASSIST_PAGE); + msr.enable = 0; + } + hv_set_msr(HV_SYN_REG_VP_ASSIST_PAGE, msr.as_uint64); + } + return 0; } diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h index d37b68238c97..108f135d4fd9 100644 --- a/include/asm-generic/mshyperv.h +++ b/include/asm-generic/mshyperv.h @@ -25,6 +25,7 @@ #include <linux/nmi.h> #include <asm/ptrace.h> #include <hyperv/hvhdk.h> +#include <hyperv/hvgdk.h> #define VTPM_BASE_ADDRESS 0xfed40000 @@ -299,6 +300,8 @@ do { \ #define hv_status_debug(status, fmt, ...) \ hv_status_printk(debug, status, fmt, ##__VA_ARGS__) +extern struct hv_vp_assist_page **hv_vp_assist_page; + const char *hv_result_to_string(u64 hv_status); int hv_result_to_errno(u64 status); void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die); @@ -377,6 +380,7 @@ static inline int hv_deposit_memory(u64 partition_id, u64 status) return hv_deposit_memory_node(NUMA_NO_NODE, partition_id, status); } +#define HV_VP_ASSIST_PAGE_ADDRESS_SHIFT 12 #if IS_ENABLED(CONFIG_HYPERV_VTL_MODE) u8 __init get_vtl(void); #else diff --git a/include/hyperv/hvgdk_mini.h b/include/hyperv/hvgdk_mini.h index 056ef7b6b360..be697ddb211a 100644 --- a/include/hyperv/hvgdk_mini.h +++ b/include/hyperv/hvgdk_mini.h @@ -149,6 +149,7 @@ struct hv_u128 { #define HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT 12 #define HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_MASK \ (~((1ull << HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT) - 1)) +#define HV_SYN_REG_VP_ASSIST_PAGE (HV_X64_MSR_VP_ASSIST_PAGE) /* Hyper-V Enlightened VMCS version mask in nested features CPUID */ #define HV_X64_ENLIGHTENED_VMCS_VERSION 0xff @@ -1185,6 +1186,7 @@ enum hv_register_name { #define HV_MSR_STIMER0_CONFIG (HV_REGISTER_STIMER0_CONFIG) #define HV_MSR_STIMER0_COUNT (HV_REGISTER_STIMER0_COUNT) +#define HV_SYN_REG_VP_ASSIST_PAGE (HV_REGISTER_VP_ASSIST_PAGE) #endif /* CONFIG_ARM64 */ -- 2.43.0
