[PATCH V5 02/12] x86/hyperv: Initialize shared memory boundary in the Isolation VM.

Tianyu Lan
2021-09-14T13:39:37Z

From: Tianyu Lan <Tianyu.Lan@microsoft.com>

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>
---
Change since v4:
* Rename reserve field.

Change since v3:
* user BIT_ULL to get shared_gpa_boundary
* Rename field Reserved* to reserved
---
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 b09ade389040..4794b716ec79 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -313,6 +313,8 @@ 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 =
+ BIT_ULL(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 0924bbd8458e..e04efb87fee5 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -35,7 +35,17 @@ 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 reserved1 : 1;
+ u32 shared_gpa_boundary_active : 1;
+ u32 shared_gpa_boundary_bits : 6;
+ u32 reserved2 : 20;
+ };
+ };
+ u64 shared_gpa_boundary;
};
extern struct ms_hyperv_info ms_hyperv;

--
2.25.1