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Diffstat (limited to 'arch/x86/hyperv/hv_init.c')
-rw-r--r--arch/x86/hyperv/hv_init.c252
1 files changed, 186 insertions, 66 deletions
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 3de6d8b53367..17a71e92a343 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -7,17 +7,22 @@
* Author : K. Y. Srinivasan <kys@microsoft.com>
*/
+#define pr_fmt(fmt) "Hyper-V: " fmt
+
#include <linux/efi.h>
#include <linux/types.h>
#include <linux/bitfield.h>
#include <linux/io.h>
#include <asm/apic.h>
#include <asm/desc.h>
+#include <asm/e820/api.h>
#include <asm/sev.h>
+#include <asm/ibt.h>
#include <asm/hypervisor.h>
#include <asm/hyperv-tlfs.h>
#include <asm/mshyperv.h>
#include <asm/idtentry.h>
+#include <asm/set_memory.h>
#include <linux/kexec.h>
#include <linux/version.h>
#include <linux/vmalloc.h>
@@ -29,7 +34,6 @@
#include <linux/syscore_ops.h>
#include <clocksource/hyperv_timer.h>
#include <linux/highmem.h>
-#include <linux/swiotlb.h>
int hyperv_init_cpuhp;
u64 hv_current_partition_id = ~0ull;
@@ -52,7 +56,7 @@ static int hyperv_init_ghcb(void)
void *ghcb_va;
void **ghcb_base;
- if (!hv_isolation_type_snp())
+ if (!ms_hyperv.paravisor_present || !hv_isolation_type_snp())
return 0;
if (!hv_ghcb_pg)
@@ -64,7 +68,10 @@ static int hyperv_init_ghcb(void)
* memory boundary and map it here.
*/
rdmsrl(MSR_AMD64_SEV_ES_GHCB, ghcb_gpa);
- ghcb_va = memremap(ghcb_gpa, HV_HYP_PAGE_SIZE, MEMREMAP_WB);
+
+ /* Mask out vTOM bit. ioremap_cache() maps decrypted */
+ ghcb_gpa &= ~ms_hyperv.shared_gpa_boundary;
+ ghcb_va = (void *)ioremap_cache(ghcb_gpa, HV_HYP_PAGE_SIZE);
if (!ghcb_va)
return -ENOMEM;
@@ -77,7 +84,7 @@ 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 = &hv_vp_assist_page[smp_processor_id()];
+ struct hv_vp_assist_page **hvp;
int ret;
ret = hv_common_cpu_init(cpu);
@@ -87,34 +94,46 @@ static int hv_cpu_init(unsigned int cpu)
if (!hv_vp_assist_page)
return 0;
- if (!*hvp) {
- 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 {
+ 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.
+ */
+ 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.
+ */
+ if (!*hvp) {
+ *hvp = __vmalloc(PAGE_SIZE, GFP_KERNEL | __GFP_ZERO);
+
/*
- * 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.
+ * 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.
*/
- *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);
+ 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;
+ wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64);
}
return hyperv_init_ghcb();
@@ -161,7 +180,7 @@ static inline bool hv_reenlightenment_available(void)
DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_reenlightenment)
{
- ack_APIC_irq();
+ apic_eoi();
inc_irq_stat(irq_hv_reenlightenment_count);
schedule_delayed_work(&hv_reenlightenment_work, HZ/10);
}
@@ -175,7 +194,7 @@ void set_hv_tscchange_cb(void (*cb)(void))
struct hv_tsc_emulation_control emu_ctrl = {.enabled = 1};
if (!hv_reenlightenment_available()) {
- pr_warn("Hyper-V: reenlightenment support is unavailable\n");
+ pr_warn("reenlightenment support is unavailable\n");
return;
}
@@ -220,7 +239,7 @@ static int hv_cpu_die(unsigned int cpu)
if (hv_ghcb_pg) {
ghcb_va = (void **)this_cpu_ptr(hv_ghcb_pg);
if (*ghcb_va)
- memunmap(*ghcb_va);
+ iounmap(*ghcb_va);
*ghcb_va = NULL;
}
@@ -268,15 +287,31 @@ static int hv_cpu_die(unsigned int cpu)
static int __init hv_pci_init(void)
{
- int gen2vm = efi_enabled(EFI_BOOT);
+ bool gen2vm = efi_enabled(EFI_BOOT);
/*
- * For Generation-2 VM, we exit from pci_arch_init() by returning 0.
- * The purpose is to suppress the harmless warning:
+ * A Generation-2 VM doesn't support legacy PCI/PCIe, so both
+ * raw_pci_ops and raw_pci_ext_ops are NULL, and pci_subsys_init() ->
+ * pcibios_init() doesn't call pcibios_resource_survey() ->
+ * e820__reserve_resources_late(); as a result, any emulated persistent
+ * memory of E820_TYPE_PRAM (12) via the kernel parameter
+ * memmap=nn[KMG]!ss is not added into iomem_resource and hence can't be
+ * detected by register_e820_pmem(). Fix this by directly calling
+ * e820__reserve_resources_late() here: e820__reserve_resources_late()
+ * depends on e820__reserve_resources(), which has been called earlier
+ * from setup_arch(). Note: e820__reserve_resources_late() also adds
+ * any memory of E820_TYPE_PMEM (7) into iomem_resource, and
+ * acpi_nfit_register_region() -> acpi_nfit_insert_resource() ->
+ * region_intersects() returns REGION_INTERSECTS, so the memory of
+ * E820_TYPE_PMEM won't get added twice.
+ *
+ * We return 0 here so that pci_arch_init() won't print the warning:
* "PCI: Fatal: No config space access function found"
*/
- if (gen2vm)
+ if (gen2vm) {
+ e820__reserve_resources_late();
return 0;
+ }
/* For Generation-1 VM, we'll proceed in pci_arch_init(). */
return 1;
@@ -378,6 +413,40 @@ static void __init hv_get_partition_id(void)
local_irq_restore(flags);
}
+#if IS_ENABLED(CONFIG_HYPERV_VTL_MODE)
+static u8 __init get_vtl(void)
+{
+ u64 control = HV_HYPERCALL_REP_COMP_1 | HVCALL_GET_VP_REGISTERS;
+ struct hv_get_vp_registers_input *input;
+ struct hv_get_vp_registers_output *output;
+ unsigned long flags;
+ u64 ret;
+
+ local_irq_save(flags);
+ input = *this_cpu_ptr(hyperv_pcpu_input_arg);
+ output = (struct hv_get_vp_registers_output *)input;
+
+ memset(input, 0, struct_size(input, element, 1));
+ input->header.partitionid = HV_PARTITION_ID_SELF;
+ input->header.vpindex = HV_VP_INDEX_SELF;
+ input->header.inputvtl = 0;
+ input->element[0].name0 = HV_X64_REGISTER_VSM_VP_STATUS;
+
+ ret = hv_do_hypercall(control, input, output);
+ if (hv_result_success(ret)) {
+ ret = output->as64.low & HV_X64_VTL_MASK;
+ } else {
+ pr_err("Failed to get VTL(error: %lld) exiting...\n", ret);
+ BUG();
+ }
+
+ local_irq_restore(flags);
+ return ret;
+}
+#else
+static inline u8 get_vtl(void) { return 0; }
+#endif
+
/*
* This function is to be invoked early in the boot sequence after the
* hypervisor has been detected.
@@ -398,14 +467,24 @@ void __init hyperv_init(void)
if (hv_common_init())
return;
- hv_vp_assist_page = kcalloc(num_possible_cpus(),
- sizeof(*hv_vp_assist_page), GFP_KERNEL);
+ /*
+ * 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 = 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 common_free;
+
+ if (!hv_isolation_type_tdx())
+ goto common_free;
}
- if (hv_isolation_type_snp()) {
+ if (ms_hyperv.paravisor_present && hv_isolation_type_snp()) {
/* Negotiate GHCB Version. */
if (!hv_ghcb_negotiate_protocol())
hv_ghcb_terminate(SEV_TERM_SET_GEN,
@@ -416,7 +495,7 @@ void __init hyperv_init(void)
goto free_vp_assist_page;
}
- cpuhp = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/hyperv_init:online",
+ cpuhp = cpuhp_setup_state(CPUHP_AP_HYPERV_ONLINE, "x86/hyperv_init:online",
hv_cpu_init, hv_cpu_die);
if (cpuhp < 0)
goto free_ghcb_page;
@@ -425,12 +504,32 @@ void __init hyperv_init(void)
* Setup the hypercall page and enable hypercalls.
* 1. Register the guest ID
* 2. Enable the hypercall and register the hypercall page
+ *
+ * A TDX VM with no paravisor only uses TDX GHCI rather than hv_hypercall_pg:
+ * when the hypercall input is a page, such a VM must pass a decrypted
+ * page to Hyper-V, e.g. hv_post_message() uses the per-CPU page
+ * hyperv_pcpu_input_arg, which is decrypted if no paravisor is present.
+ *
+ * A TDX VM with the paravisor uses hv_hypercall_pg for most hypercalls,
+ * which are handled by the paravisor and the VM must use an encrypted
+ * input page: in such a VM, the hyperv_pcpu_input_arg is encrypted and
+ * used in the hypercalls, e.g. see hv_mark_gpa_visibility() and
+ * hv_arch_irq_unmask(). Such a VM uses TDX GHCI for two hypercalls:
+ * 1. HVCALL_SIGNAL_EVENT: see vmbus_set_event() and _hv_do_fast_hypercall8().
+ * 2. HVCALL_POST_MESSAGE: the input page must be a decrypted page, i.e.
+ * hv_post_message() in such a VM can't use the encrypted hyperv_pcpu_input_arg;
+ * instead, hv_post_message() uses the post_msg_page, which is decrypted
+ * in such a VM and is only used in such a VM.
*/
- guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0);
+ guest_id = hv_generate_guest_id(LINUX_VERSION_CODE);
wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id);
- /* Hyper-V requires to write guest os id via ghcb in SNP IVM. */
- hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, guest_id);
+ /* With the paravisor, the VM must also write the ID via GHCB/GHCI */
+ hv_ivm_msr_write(HV_X64_MSR_GUEST_OS_ID, guest_id);
+
+ /* A TDX VM with no paravisor only uses TDX GHCI rather than hv_hypercall_pg */
+ if (hv_isolation_type_tdx() && !ms_hyperv.paravisor_present)
+ goto skip_hypercall_pg_init;
hv_hypercall_pg = __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START,
VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_ROX,
@@ -444,7 +543,7 @@ void __init hyperv_init(void)
if (hv_root_partition) {
struct page *pg;
- void *src, *dst;
+ void *src;
/*
* For the root partition, the hypervisor will set up its
@@ -459,18 +558,39 @@ void __init hyperv_init(void)
wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
pg = vmalloc_to_page(hv_hypercall_pg);
- dst = kmap(pg);
src = memremap(hypercall_msr.guest_physical_address << PAGE_SHIFT, PAGE_SIZE,
MEMREMAP_WB);
- BUG_ON(!(src && dst));
- memcpy(dst, src, HV_HYP_PAGE_SIZE);
+ BUG_ON(!src);
+ memcpy_to_page(pg, 0, src, HV_HYP_PAGE_SIZE);
memunmap(src);
- kunmap(pg);
+
+ hv_remap_tsc_clocksource();
} else {
hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg);
wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
}
+skip_hypercall_pg_init:
+ /*
+ * Some versions of Hyper-V that provide IBT in guest VMs have a bug
+ * in that there's no ENDBR64 instruction at the entry to the
+ * hypercall page. Because hypercalls are invoked via an indirect call
+ * to the hypercall page, all hypercall attempts fail when IBT is
+ * enabled, and Linux panics. For such buggy versions, disable IBT.
+ *
+ * Fixed versions of Hyper-V always provide ENDBR64 on the hypercall
+ * page, so if future Linux kernel versions enable IBT for 32-bit
+ * builds, additional hypercall page hackery will be required here
+ * to provide an ENDBR32.
+ */
+#ifdef CONFIG_X86_KERNEL_IBT
+ if (cpu_feature_enabled(X86_FEATURE_IBT) &&
+ *(u32 *)hv_hypercall_pg != gen_endbr()) {
+ setup_clear_cpu_cap(X86_FEATURE_IBT);
+ pr_warn("Disabling IBT because of Hyper-V bug\n");
+ }
+#endif
+
/*
* hyperv_init() is called before LAPIC is initialized: see
* apic_intr_mode_init() -> x86_platform.apic_post_init() and
@@ -506,21 +626,17 @@ void __init hyperv_init(void)
/* Query the VMs extended capability once, so that it can be cached. */
hv_query_ext_cap(0);
-#ifdef CONFIG_SWIOTLB
- /*
- * Swiotlb bounce buffer needs to be mapped in extra address
- * space. Map function doesn't work in the early place and so
- * call swiotlb_update_mem_attributes() here.
- */
- if (hv_is_isolation_supported())
- swiotlb_update_mem_attributes();
-#endif
+ /* Find the VTL */
+ ms_hyperv.vtl = get_vtl();
+
+ if (ms_hyperv.vtl > 0) /* non default VTL */
+ hv_vtl_early_init();
return;
clean_guest_os_id:
wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
- hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, 0);
+ hv_ivm_msr_write(HV_X64_MSR_GUEST_OS_ID, 0);
cpuhp_remove_state(cpuhp);
free_ghcb_page:
free_percpu(hv_ghcb_pg);
@@ -537,12 +653,11 @@ common_free:
void hyperv_cleanup(void)
{
union hv_x64_msr_hypercall_contents hypercall_msr;
-
- unregister_syscore_ops(&hv_syscore_ops);
+ union hv_reference_tsc_msr tsc_msr;
/* Reset our OS id */
wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
- hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, 0);
+ hv_ivm_msr_write(HV_X64_MSR_GUEST_OS_ID, 0);
/*
* Reset hypercall page reference before reset the page,
@@ -552,12 +667,14 @@ void hyperv_cleanup(void)
hv_hypercall_pg = NULL;
/* Reset the hypercall page */
- hypercall_msr.as_uint64 = 0;
- wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+ hypercall_msr.as_uint64 = hv_get_msr(HV_X64_MSR_HYPERCALL);
+ hypercall_msr.enable = 0;
+ hv_set_msr(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
/* Reset the TSC page */
- hypercall_msr.as_uint64 = 0;
- wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64);
+ tsc_msr.as_uint64 = hv_get_msr(HV_X64_MSR_REFERENCE_TSC);
+ tsc_msr.enable = 0;
+ hv_set_msr(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
}
void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die)
@@ -603,6 +720,9 @@ bool hv_is_hyperv_initialized(void)
if (x86_hyper_type != X86_HYPER_MS_HYPERV)
return false;
+ /* A TDX VM with no paravisor uses TDX GHCI call rather than hv_hypercall_pg */
+ if (hv_isolation_type_tdx() && !ms_hyperv.paravisor_present)
+ return true;
/*
* Verify that earlier initialization succeeded by checking
* that the hypercall page is setup
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.