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| author | Jinank Jain <jinankjain@linux.microsoft.com> | 2023-01-02 07:12:51 +0000 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2023-01-12 15:23:26 +0000 |
| commit | c4bdf94f97c86bdee8bacc87f8f85dc67866c928 (patch) | |
| tree | 0fb80013913a5eb1966a31e39e7771120cdcb7e9 /arch | |
| parent | b7bfaa761d760e72a969d116517eaa12e404c262 (diff) | |
| download | linux-stable-c4bdf94f97c86bdee8bacc87f8f85dc67866c928.tar.gz linux-stable-c4bdf94f97c86bdee8bacc87f8f85dc67866c928.tar.bz2 linux-stable-c4bdf94f97c86bdee8bacc87f8f85dc67866c928.zip | |
x86/hyperv: Add support for detecting nested hypervisor
Detect if Linux is running as a nested hypervisor in the root
partition for Microsoft Hypervisor, using flags provided by MSHV.
Expose a new variable hv_nested that is used later for decisions
specific to the nested use case.
Signed-off-by: Jinank Jain <jinankjain@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/8e3e7112806e81d2292a66a56fe547162754ecea.1672639707.git.jinankjain@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/hyperv-tlfs.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mshyperv.c | 7 |
2 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h index 08e822bd7aa6..724a2589c0e7 100644 --- a/arch/x86/include/asm/hyperv-tlfs.h +++ b/arch/x86/include/asm/hyperv-tlfs.h @@ -116,6 +116,9 @@ /* Recommend using the newer ExProcessorMasks interface */ #define HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED BIT(11) +/* Indicates that the hypervisor is nested within a Hyper-V partition. */ +#define HV_X64_HYPERV_NESTED BIT(12) + /* Recommend using enlightened VMCS */ #define HV_X64_ENLIGHTENED_VMCS_RECOMMENDED BIT(14) diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 46668e255421..f9b78d4829e3 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -37,6 +37,8 @@ /* Is Linux running as the root partition? */ bool hv_root_partition; +/* Is Linux running on nested Microsoft Hypervisor */ +bool hv_nested; struct ms_hyperv_info ms_hyperv; #if IS_ENABLED(CONFIG_HYPERV) @@ -301,6 +303,11 @@ static void __init ms_hyperv_init_platform(void) pr_info("Hyper-V: running as root partition\n"); } + if (ms_hyperv.hints & HV_X64_HYPERV_NESTED) { + hv_nested = true; + pr_info("Hyper-V: running on a nested hypervisor\n"); + } + /* * Extract host information. */ |