diff options
| -rw-r--r-- | arch/x86/hyperv/hv_init.c | 64 | ||||
| -rw-r--r-- | arch/x86/include/asm/hyperv-tlfs.h | 9 |
2 files changed, 53 insertions, 20 deletions
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index 6f247e7e07eb..708a2712a516 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -44,6 +44,7 @@ EXPORT_SYMBOL_GPL(hv_vp_assist_page); static int hv_cpu_init(unsigned int cpu) { + union hv_vp_assist_msr_contents msr = { 0 }; struct hv_vp_assist_page **hvp = &hv_vp_assist_page[smp_processor_id()]; int ret; @@ -54,25 +55,34 @@ static int hv_cpu_init(unsigned int cpu) if (!hv_vp_assist_page) return 0; - /* - * 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); - } - - if (*hvp) { - u64 val; - - val = vmalloc_to_pfn(*hvp); - val = (val << HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT) | - HV_X64_MSR_VP_ASSIST_PAGE_ENABLE; - - wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, val); + if (hv_root_partition) { + /* + * For root partition we get the hypervisor provided VP assist + * page, instead of allocating a new page. + */ + rdmsrl(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. + */ + *hvp = __vmalloc(PAGE_SIZE, GFP_KERNEL | __GFP_ZERO); + if (*hvp) + msr.pfn = vmalloc_to_pfn(*hvp); + } + WARN_ON(!(*hvp)); + if (*hvp) { + msr.enable = 1; + wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64); + } } return 0; @@ -170,8 +180,22 @@ static int hv_cpu_die(unsigned int cpu) hv_common_cpu_die(cpu); - if (hv_vp_assist_page && hv_vp_assist_page[cpu]) - wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, 0); + 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; + rdmsrl(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64); + msr.enable = 0; + } + wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64); + } if (hv_reenlightenment_cb == NULL) return 0; diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h index f1366ce609e3..2322d6bd5883 100644 --- a/arch/x86/include/asm/hyperv-tlfs.h +++ b/arch/x86/include/asm/hyperv-tlfs.h @@ -288,6 +288,15 @@ union hv_x64_msr_hypercall_contents { } __packed; }; +union hv_vp_assist_msr_contents { + u64 as_uint64; + struct { + u64 enable:1; + u64 reserved:11; + u64 pfn:52; + } __packed; +}; + struct hv_reenlightenment_control { __u64 vector:8; __u64 reserved1:8; |