From a46d15cc1ae5af905afac2af4cc0c188c2eb59b0 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Tue, 20 Mar 2018 15:02:08 +0100 Subject: x86/hyper-v: allocate and use Virtual Processor Assist Pages MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Virtual Processor Assist Pages usage allows us to do optimized EOI processing for APIC, enable Enlightened VMCS support in KVM and more. struct hv_vp_assist_page is defined according to the Hyper-V TLFS v5.0b. Signed-off-by: Vitaly Kuznetsov Reviewed-by: Thomas Gleixner Acked-by: Thomas Gleixner Signed-off-by: Radim Krčmář --- arch/x86/hyperv/hv_init.c | 43 ++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 40 insertions(+), 3 deletions(-) (limited to 'arch/x86/hyperv') diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index 4b82bc206929..cfecc2272f2d 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -88,11 +88,15 @@ EXPORT_SYMBOL_GPL(hyperv_cs); u32 *hv_vp_index; EXPORT_SYMBOL_GPL(hv_vp_index); +struct hv_vp_assist_page **hv_vp_assist_page; +EXPORT_SYMBOL_GPL(hv_vp_assist_page); + u32 hv_max_vp_index; static int hv_cpu_init(unsigned int cpu) { u64 msr_vp_index; + struct hv_vp_assist_page **hvp = &hv_vp_assist_page[smp_processor_id()]; hv_get_vp_index(msr_vp_index); @@ -101,6 +105,22 @@ static int hv_cpu_init(unsigned int cpu) if (msr_vp_index > hv_max_vp_index) hv_max_vp_index = msr_vp_index; + if (!hv_vp_assist_page) + return 0; + + if (!*hvp) + *hvp = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL); + + 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); + } + return 0; } @@ -198,6 +218,9 @@ static int hv_cpu_die(unsigned int cpu) struct hv_reenlightenment_control re_ctrl; unsigned int new_cpu; + if (hv_vp_assist_page && hv_vp_assist_page[cpu]) + wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, 0); + if (hv_reenlightenment_cb == NULL) return 0; @@ -224,6 +247,7 @@ void hyperv_init(void) { u64 guest_id, required_msrs; union hv_x64_msr_hypercall_contents hypercall_msr; + int cpuhp; if (x86_hyper_type != X86_HYPER_MS_HYPERV) return; @@ -241,9 +265,17 @@ void hyperv_init(void) if (!hv_vp_index) return; - if (cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/hyperv_init:online", - hv_cpu_init, hv_cpu_die) < 0) + hv_vp_assist_page = kcalloc(num_possible_cpus(), + sizeof(*hv_vp_assist_page), GFP_KERNEL); + if (!hv_vp_assist_page) { + ms_hyperv.hints &= ~HV_X64_ENLIGHTENED_VMCS_RECOMMENDED; goto free_vp_index; + } + + cpuhp = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/hyperv_init:online", + hv_cpu_init, hv_cpu_die); + if (cpuhp < 0) + goto free_vp_assist_page; /* * Setup the hypercall page and enable hypercalls. @@ -256,7 +288,7 @@ void hyperv_init(void) hv_hypercall_pg = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_RX); if (hv_hypercall_pg == NULL) { wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0); - goto free_vp_index; + goto remove_cpuhp_state; } rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); @@ -304,6 +336,11 @@ register_msr_cs: return; +remove_cpuhp_state: + cpuhp_remove_state(cpuhp); +free_vp_assist_page: + kfree(hv_vp_assist_page); + hv_vp_assist_page = NULL; free_vp_index: kfree(hv_vp_index); hv_vp_index = NULL; -- cgit v1.2.3-59-g8ed1b