[PATCH v7 01/13] KVM: TDX: Flush cache based on page size before TDX SEAMCALL

From: isaku . yamahata
Date: Mon Jan 22 2024 - 20:02:18 EST


From: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>

tdh_mem_page_aug() will support 2MB large page in the near future. Cache
flush also needs to be 2MB instead of 4KB in such cases. Introduce a
helper function to flush cache with page size info in preparation for large
pages.

Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Reviewed-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>
---
v6:
- catch up tdx_seamcall() change
---
arch/x86/kvm/vmx/tdx_ops.h | 22 ++++++++++++++--------
1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/vmx/tdx_ops.h b/arch/x86/kvm/vmx/tdx_ops.h
index 3513d5df10ee..2afd927eaa45 100644
--- a/arch/x86/kvm/vmx/tdx_ops.h
+++ b/arch/x86/kvm/vmx/tdx_ops.h
@@ -6,6 +6,7 @@

#include <linux/compiler.h>

+#include <asm/pgtable_types.h>
#include <asm/archrandom.h>
#include <asm/cacheflush.h>
#include <asm/asm.h>
@@ -58,6 +59,11 @@ static inline int pg_level_to_tdx_sept_level(enum pg_level level)
return level - 1;
}

+static inline void tdx_clflush_page(hpa_t addr, enum pg_level level)
+{
+ clflush_cache_range(__va(addr), KVM_HPAGE_SIZE(level));
+}
+
/*
* TDX module acquires its internal lock for resources. It doesn't spin to get
* locks because of its restrictions of allowed execution time. Instead, it
@@ -95,7 +101,7 @@ static inline u64 tdh_mng_addcx(hpa_t tdr, hpa_t addr)
.rdx = tdr,
};

- clflush_cache_range(__va(addr), PAGE_SIZE);
+ tdx_clflush_page(addr, PG_LEVEL_4K);
return tdx_seamcall(TDH_MNG_ADDCX, &in, NULL);
}

@@ -109,7 +115,7 @@ static inline u64 tdh_mem_page_add(hpa_t tdr, gpa_t gpa, hpa_t hpa, hpa_t source
.r9 = source,
};

- clflush_cache_range(__va(hpa), PAGE_SIZE);
+ tdx_clflush_page(hpa, PG_LEVEL_4K);
return tdx_seamcall_sept(TDH_MEM_PAGE_ADD, &in, out);
}

@@ -122,7 +128,7 @@ static inline u64 tdh_mem_sept_add(hpa_t tdr, gpa_t gpa, int level, hpa_t page,
.r8 = page,
};

- clflush_cache_range(__va(page), PAGE_SIZE);
+ tdx_clflush_page(page, PG_LEVEL_4K);
return tdx_seamcall_sept(TDH_MEM_SEPT_ADD, &in, out);
}

@@ -155,7 +161,7 @@ static inline u64 tdh_vp_addcx(hpa_t tdvpr, hpa_t addr)
.rdx = tdvpr,
};

- clflush_cache_range(__va(addr), PAGE_SIZE);
+ tdx_clflush_page(addr, PG_LEVEL_4K);
return tdx_seamcall(TDH_VP_ADDCX, &in, NULL);
}

@@ -168,7 +174,7 @@ static inline u64 tdh_mem_page_relocate(hpa_t tdr, gpa_t gpa, hpa_t hpa,
.r8 = hpa,
};

- clflush_cache_range(__va(hpa), PAGE_SIZE);
+ tdx_clflush_page(hpa, PG_LEVEL_4K);
return tdx_seamcall_sept(TDH_MEM_PAGE_RELOCATE, &in, out);
}

@@ -181,7 +187,7 @@ static inline u64 tdh_mem_page_aug(hpa_t tdr, gpa_t gpa, hpa_t hpa,
.r8 = hpa,
};

- clflush_cache_range(__va(hpa), PAGE_SIZE);
+ tdx_clflush_page(hpa, PG_LEVEL_4K);
return tdx_seamcall_sept(TDH_MEM_PAGE_AUG, &in, out);
}

@@ -212,7 +218,7 @@ static inline u64 tdh_mng_create(hpa_t tdr, int hkid)
.rdx = hkid,
};

- clflush_cache_range(__va(tdr), PAGE_SIZE);
+ tdx_clflush_page(tdr, PG_LEVEL_4K);
return tdx_seamcall(TDH_MNG_CREATE, &in, NULL);
}

@@ -223,7 +229,7 @@ static inline u64 tdh_vp_create(hpa_t tdr, hpa_t tdvpr)
.rdx = tdr,
};

- clflush_cache_range(__va(tdvpr), PAGE_SIZE);
+ tdx_clflush_page(tdvpr, PG_LEVEL_4K);
return tdx_seamcall(TDH_VP_CREATE, &in, NULL);
}

--
2.25.1