x86/hyperv: Fix the detection of E820_TYPE_PRAM in a Gen2 VM

[platform/kernel/linux-starfive.git] / arch / x86 / hyperv / hv_init.c

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 783ed33..8f3a4d1 100644 (file)
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -7,12 +7,15 @@
  * 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>
@@ -191,7 +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;
        }
 
@@ -284,15 +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;
@@ -394,6 +413,7 @@ 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;
@@ -416,13 +436,16 @@ static u8 __init get_vtl(void)
        if (hv_result_success(ret)) {
                ret = output->as64.low & HV_X64_VTL_MASK;
        } else {
-               pr_err("Failed to get VTL(%lld) and set VTL to zero by default.\n", ret);
-               ret = 0;
+               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
@@ -564,7 +587,7 @@ skip_hypercall_pg_init:
        if (cpu_feature_enabled(X86_FEATURE_IBT) &&
            *(u32 *)hv_hypercall_pg != gen_endbr()) {
                setup_clear_cpu_cap(X86_FEATURE_IBT);
-               pr_warn("Hyper-V: Disabling IBT because of Hyper-V bug\n");
+               pr_warn("Disabling IBT because of Hyper-V bug\n");
        }
 #endif
 
@@ -604,8 +627,10 @@ skip_hypercall_pg_init:
        hv_query_ext_cap(0);
 
        /* Find the VTL */
-       if (!ms_hyperv.paravisor_present && hv_isolation_type_snp())
-               ms_hyperv.vtl = get_vtl();
+       ms_hyperv.vtl = get_vtl();
+
+       if (ms_hyperv.vtl > 0) /* non default VTL */
+               hv_vtl_early_init();
 
        return;