[Resend RFC PATCH V4 02/13] x86/HV: Initialize shared memory boundary in the Isolation VM.

Tianyu Lan
2021-07-07T15:47:03Z

Hyper-V exposes shared memory boundary via cpuid
HYPERV_CPUID_ISOLATION_CONFIG and store it in the
shared_gpa_boundary of ms_hyperv struct. This prepares
to share memory with host for SNP guest.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
arch/x86/kernel/cpu/mshyperv.c | 2 ++
include/asm-generic/mshyperv.h | 12 +++++++++++-
2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 10b2a8c10cb6..8aed689db621 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -334,6 +334,8 @@ static void __init ms_hyperv_init_platform(void)
if (ms_hyperv.priv_high & HV_ISOLATION) {
ms_hyperv.isolation_config_a = cpuid_eax(HYPERV_CPUID_ISOLATION_CONFIG);
ms_hyperv.isolation_config_b = cpuid_ebx(HYPERV_CPUID_ISOLATION_CONFIG);
+ ms_hyperv.shared_gpa_boundary =
+ (u64)1 << ms_hyperv.shared_gpa_boundary_bits;

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);
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 3ae56a29594f..2914e27b0429 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -34,8 +34,18 @@ struct ms_hyperv_info {
u32 max_vp_index;
u32 max_lp_index;
u32 isolation_config_a;
- u32 isolation_config_b;
+ union {
+ u32 isolation_config_b;
+ struct {
+ u32 cvm_type : 4;
+ u32 Reserved11 : 1;
+ u32 shared_gpa_boundary_active : 1;
+ u32 shared_gpa_boundary_bits : 6;
+ u32 Reserved12 : 20;
+ };
+ };
void __percpu **ghcb_base;
+ u64 shared_gpa_boundary;
};
extern struct ms_hyperv_info ms_hyperv;

--
2.25.1