[RFC PATCH v2 02/15] KVM: TDX: Pass page level to cache flush before TDX SEAMCALL

From: isaku . yamahata
Date: Thu Dec 08 2022 - 18:36:05 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>
---
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 86330d0e4b22..4db983b1dc94 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/cacheflush.h>
#include <asm/asm.h>
#include <asm/kvm_host.h>
@@ -18,6 +19,11 @@

void pr_tdx_error(u64 op, u64 error_code, const struct tdx_module_output *out);

+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
@@ -50,21 +56,21 @@ static inline u64 seamcall_sept(u64 op, u64 rcx, u64 rdx, u64 r8, u64 r9,

static inline u64 tdh_mng_addcx(hpa_t tdr, hpa_t addr)
{
- clflush_cache_range(__va(addr), PAGE_SIZE);
+ tdx_clflush_page(addr, PG_LEVEL_4K);
return __seamcall(TDH_MNG_ADDCX, addr, tdr, 0, 0, NULL);
}

static inline u64 tdh_mem_page_add(hpa_t tdr, gpa_t gpa, hpa_t hpa, hpa_t source,
struct tdx_module_output *out)
{
- clflush_cache_range(__va(hpa), PAGE_SIZE);
+ tdx_clflush_page(hpa, PG_LEVEL_4K);
return seamcall_sept(TDH_MEM_PAGE_ADD, gpa, tdr, hpa, source, out);
}

static inline u64 tdh_mem_sept_add(hpa_t tdr, gpa_t gpa, int level, hpa_t page,
struct tdx_module_output *out)
{
- clflush_cache_range(__va(page), PAGE_SIZE);
+ tdx_clflush_page(page, PG_LEVEL_4K);
return seamcall_sept(TDH_MEM_SEPT_ADD, gpa | level, tdr, page, 0, out);
}

@@ -76,21 +82,21 @@ static inline u64 tdh_mem_sept_remove(hpa_t tdr, gpa_t gpa, int level,

static inline u64 tdh_vp_addcx(hpa_t tdvpr, hpa_t addr)
{
- clflush_cache_range(__va(addr), PAGE_SIZE);
+ tdx_clflush_page(addr, PG_LEVEL_4K);
return __seamcall(TDH_VP_ADDCX, addr, tdvpr, 0, 0, NULL);
}

static inline u64 tdh_mem_page_relocate(hpa_t tdr, gpa_t gpa, hpa_t hpa,
struct tdx_module_output *out)
{
- clflush_cache_range(__va(hpa), PAGE_SIZE);
+ tdx_clflush_page(hpa, PG_LEVEL_4K);
return __seamcall(TDH_MEM_PAGE_RELOCATE, gpa, tdr, hpa, 0, out);
}

static inline u64 tdh_mem_page_aug(hpa_t tdr, gpa_t gpa, hpa_t hpa,
struct tdx_module_output *out)
{
- clflush_cache_range(__va(hpa), PAGE_SIZE);
+ tdx_clflush_page(hpa, PG_LEVEL_4K);
return seamcall_sept(TDH_MEM_PAGE_AUG, gpa, tdr, hpa, 0, out);
}

@@ -107,13 +113,13 @@ static inline u64 tdh_mng_key_config(hpa_t tdr)

static inline u64 tdh_mng_create(hpa_t tdr, int hkid)
{
- clflush_cache_range(__va(tdr), PAGE_SIZE);
+ tdx_clflush_page(tdr, PG_LEVEL_4K);
return __seamcall(TDH_MNG_CREATE, tdr, hkid, 0, 0, NULL);
}

static inline u64 tdh_vp_create(hpa_t tdr, hpa_t tdvpr)
{
- clflush_cache_range(__va(tdvpr), PAGE_SIZE);
+ tdx_clflush_page(tdvpr, PG_LEVEL_4K);
return __seamcall(TDH_VP_CREATE, tdvpr, tdr, 0, 0, NULL);
}

--
2.25.1