Merge tag 'hyperv-next-signed-20210216' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull Hyper-V updates from Wei Liu:

 - VMBus hardening patches from Andrea Parri and Andres Beltran.

 - Patches to make Linux boot as the root partition on Microsoft
   Hypervisor from Wei Liu.

 - One patch to add a new sysfs interface to support hibernation on
   Hyper-V from Dexuan Cui.

 - Two miscellaneous clean-up patches from Colin and Gustavo.

* tag 'hyperv-next-signed-20210216' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (31 commits)
  Revert "Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer"
  iommu/hyperv: setup an IO-APIC IRQ remapping domain for root partition
  x86/hyperv: implement an MSI domain for root partition
  asm-generic/hyperv: import data structures for mapping device interrupts
  asm-generic/hyperv: introduce hv_device_id and auxiliary structures
  asm-generic/hyperv: update hv_interrupt_entry
  asm-generic/hyperv: update hv_msi_entry
  x86/hyperv: implement and use hv_smp_prepare_cpus
  x86/hyperv: provide a bunch of helper functions
  ACPI / NUMA: add a stub function for node_to_pxm()
  x86/hyperv: handling hypercall page setup for root
  x86/hyperv: extract partition ID from Microsoft Hypervisor if necessary
  x86/hyperv: allocate output arg pages if required
  clocksource/hyperv: use MSR-based access if running as root
  Drivers: hv: vmbus: skip VMBus initialization if Linux is root
  x86/hyperv: detect if Linux is the root partition
  asm-generic/hyperv: change HV_CPU_POWER_MANAGEMENT to HV_CPU_MANAGEMENT
  hv: hyperv.h: Replace one-element array with flexible-array in struct icmsg_negotiate
  hv_netvsc: Restrict configurations on isolated guests
  Drivers: hv: vmbus: Enforce 'VMBus version >= 5.2' on isolated guests
  ...

1 files changed, 58 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 43b54bef5448..e88bc296afca 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -31,6 +31,11 @@
 #include <asm/reboot.h>
 #include <asm/nmi.h>
 #include <clocksource/hyperv_timer.h>
+#include <asm/numa.h>
+
+/* Is Linux running as the root partition? */
+bool hv_root_partition;
+EXPORT_SYMBOL_GPL(hv_root_partition);
 
 struct ms_hyperv_info ms_hyperv;
 EXPORT_SYMBOL_GPL(ms_hyperv);
@@ -226,6 +231,32 @@ static void __init hv_smp_prepare_boot_cpu(void)
 	hv_init_spinlocks();
 #endif
 }
+
+static void __init hv_smp_prepare_cpus(unsigned int max_cpus)
+{
+#ifdef CONFIG_X86_64
+	int i;
+	int ret;
+#endif
+
+	native_smp_prepare_cpus(max_cpus);
+
+#ifdef CONFIG_X86_64
+	for_each_present_cpu(i) {
+		if (i == 0)
+			continue;
+		ret = hv_call_add_logical_proc(numa_cpu_node(i), i, cpu_physical_id(i));
+		BUG_ON(ret);
+	}
+
+	for_each_present_cpu(i) {
+		if (i == 0)
+			continue;
+		ret = hv_call_create_vp(numa_cpu_node(i), hv_current_partition_id, i, i);
+		BUG_ON(ret);
+	}
+#endif
+}
 #endif
 
 static void __init ms_hyperv_init_platform(void)
@@ -243,6 +274,7 @@ static void __init ms_hyperv_init_platform(void)
 	 * Extract the features and hints
 	 */
 	ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
+	ms_hyperv.features_b = cpuid_ebx(HYPERV_CPUID_FEATURES);
 	ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES);
 	ms_hyperv.hints    = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
 
@@ -256,6 +288,22 @@ static void __init ms_hyperv_init_platform(void)
 		 ms_hyperv.max_vp_index, ms_hyperv.max_lp_index);
 
 	/*
+	 * Check CPU management privilege.
+	 *
+	 * To mirror what Windows does we should extract CPU management
+	 * features and use the ReservedIdentityBit to detect if Linux is the
+	 * root partition. But that requires negotiating CPU management
+	 * interface (a process to be finalized).
+	 *
+	 * For now, use the privilege flag as the indicator for running as
+	 * root.
+	 */
+	if (cpuid_ebx(HYPERV_CPUID_FEATURES) & HV_CPU_MANAGEMENT) {
+		hv_root_partition = true;
+		pr_info("Hyper-V: running as root partition\n");
+	}
+
+	/*
 	 * Extract host information.
 	 */
 	if (cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS) >=
@@ -277,6 +325,14 @@ static void __init ms_hyperv_init_platform(void)
 		x86_platform.calibrate_cpu = hv_get_tsc_khz;
 	}
 
+	if (ms_hyperv.features_b & HV_ISOLATION) {
+		ms_hyperv.isolation_config_a = cpuid_eax(HYPERV_CPUID_ISOLATION_CONFIG);
+		ms_hyperv.isolation_config_b = cpuid_ebx(HYPERV_CPUID_ISOLATION_CONFIG);
+
+		pr_info("Hyper-V: Isolation Config: Group A 0x%x, Group B 0x%x\n",
+			ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b);
+	}
+
 	if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED) {
 		ms_hyperv.nested_features =
 			cpuid_eax(HYPERV_CPUID_NESTED_FEATURES);
@@ -366,6 +422,8 @@ static void __init ms_hyperv_init_platform(void)
 
 # ifdef CONFIG_SMP
 	smp_ops.smp_prepare_boot_cpu = hv_smp_prepare_boot_cpu;
+	if (hv_root_partition)
+		smp_ops.smp_prepare_cpus = hv_smp_prepare_cpus;
 # endif
 
 	/*