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authorDexuan Cui <decui@microsoft.com>2023-08-24 01:07:04 -0700
committerWei Liu <wei.liu@kernel.org>2023-08-25 00:04:56 +0000
commitd6e0228d265f29348a01780ff306321c399d8b95 (patch)
tree5c05fed6d87e9444003f911e73389ce926def88c /arch/x86/hyperv/hv_init.c
parent08e9d12077fcc7c4c4579d7dcd8093b59b01369e (diff)
x86/hyperv: Support hypercalls for fully enlightened TDX guests
A fully enlightened TDX guest on Hyper-V (i.e. without the paravisor) only uses the GHCI call rather than hv_hypercall_pg. Do not initialize hypercall_pg for such a guest. In hv_common_cpu_init(), the hyperv_pcpu_input_arg page needs to be decrypted in such a guest. Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230824080712.30327-3-decui@microsoft.com
Diffstat (limited to 'arch/x86/hyperv/hv_init.c')
-rw-r--r--arch/x86/hyperv/hv_init.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index bcfbcda8b050..255e02ec467e 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -476,6 +476,10 @@ void __init hyperv_init(void)
/* 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);
+ /* A TDX guest uses the GHCI call rather than hv_hypercall_pg. */
+ if (hv_isolation_type_tdx())
+ goto skip_hypercall_pg_init;
+
hv_hypercall_pg = __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START,
VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_ROX,
VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
@@ -515,6 +519,7 @@ void __init hyperv_init(void)
wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
}
+skip_hypercall_pg_init:
/*
* hyperv_init() is called before LAPIC is initialized: see
* apic_intr_mode_init() -> x86_platform.apic_post_init() and
@@ -642,6 +647,9 @@ bool hv_is_hyperv_initialized(void)
if (x86_hyper_type != X86_HYPER_MS_HYPERV)
return false;
+ /* A TDX guest uses the GHCI call rather than hv_hypercall_pg. */
+ if (hv_isolation_type_tdx())
+ return true;
/*
* Verify that earlier initialization succeeded by checking
* that the hypercall page is setup