--- v4
+++ v3
@@ -1,180 +1,71 @@
From: Tianyu Lan <Tianyu.Lan@microsoft.com>
-In Isolation VM with AMD SEV, bounce buffer needs to be accessed via
-extra address space which is above shared_gpa_boundary
-(E.G 39 bit address line) reported by Hyper-V CPUID ISOLATION_CONFIG.
-The access physical address will be original physical address +
-shared_gpa_boundary. The shared_gpa_boundary in the AMD SEV SNP
-spec is called virtual top of memory(vTOM). Memory addresses below
-vTOM are automatically treated as private while memory above
-vTOM is treated as shared.
-
-Introduce set_memory_decrypted_map() function to decrypt memory and
-remap memory with platform callback. Use set_memory_decrypted_
-map() in the swiotlb code, store remap address returned by the new
-API and use the remap address to copy data from/to swiotlb bounce buffer.
+For Hyper-V isolation VM with AMD SEV SNP, the bounce buffer(shared memory)
+needs to be accessed via extra address space(e.g address above bit39).
+Hyper-V code may remap extra address space outside of swiotlb. swiotlb_
+bounce() needs to use remap virtual address to copy data from/to bounce
+buffer. Add new interface swiotlb_set_bounce_remap() to do that.
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
- arch/x86/hyperv/ivm.c | 30 ++++++++++++++++++++++++++++++
- arch/x86/include/asm/mshyperv.h | 2 ++
- arch/x86/include/asm/set_memory.h | 2 ++
- arch/x86/mm/pat/set_memory.c | 28 ++++++++++++++++++++++++++++
- include/linux/swiotlb.h | 4 ++++
- kernel/dma/swiotlb.c | 11 ++++++++---
- 6 files changed, 74 insertions(+), 3 deletions(-)
+ include/linux/swiotlb.h | 5 +++++
+ kernel/dma/swiotlb.c | 14 +++++++++++++-
+ 2 files changed, 18 insertions(+), 1 deletion(-)
-diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
-index 8a6f4e9e3d6c..ea33935e0c17 100644
---- a/arch/x86/hyperv/ivm.c
-+++ b/arch/x86/hyperv/ivm.c
-@@ -267,3 +267,33 @@ int hv_set_mem_enc(unsigned long addr, int numpages, bool enc)
- enc ? VMBUS_PAGE_NOT_VISIBLE
- : VMBUS_PAGE_VISIBLE_READ_WRITE);
- }
-+
-+/*
-+ * hv_map_memory - map memory to extra space in the AMD SEV-SNP Isolation VM.
-+ */
-+unsigned long hv_map_memory(unsigned long addr, unsigned long size)
+diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
+index 216854a5e513..43f53cf52f48 100644
+--- a/include/linux/swiotlb.h
++++ b/include/linux/swiotlb.h
+@@ -113,8 +113,13 @@ unsigned int swiotlb_max_segment(void);
+ size_t swiotlb_max_mapping_size(struct device *dev);
+ bool is_swiotlb_active(void);
+ void __init swiotlb_adjust_size(unsigned long size);
++void swiotlb_set_bounce_remap(unsigned char *vaddr);
+ #else
+ #define swiotlb_force SWIOTLB_NO_FORCE
++static inline void swiotlb_set_bounce_remap(unsigned char *vaddr)
+{
-+ unsigned long *pfns = kcalloc(size / HV_HYP_PAGE_SIZE,
-+ sizeof(unsigned long),
-+ GFP_KERNEL);
-+ unsigned long vaddr;
-+ int i;
-+
-+ if (!pfns)
-+ return (unsigned long)NULL;
-+
-+ for (i = 0; i < size / HV_HYP_PAGE_SIZE; i++)
-+ pfns[i] = virt_to_hvpfn((void *)addr + i * HV_HYP_PAGE_SIZE) +
-+ (ms_hyperv.shared_gpa_boundary >> HV_HYP_PAGE_SHIFT);
-+
-+ vaddr = (unsigned long)vmap_pfn(pfns, size / HV_HYP_PAGE_SIZE,
-+ PAGE_KERNEL_IO);
-+ kfree(pfns);
-+
-+ return vaddr;
+}
+
-+void hv_unmap_memory(unsigned long addr)
+ static inline bool is_swiotlb_buffer(phys_addr_t paddr)
+ {
+ return false;
+diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
+index 8ca7d505d61c..fbc827ab5fb4 100644
+--- a/kernel/dma/swiotlb.c
++++ b/kernel/dma/swiotlb.c
+@@ -70,6 +70,7 @@ struct io_tlb_mem *io_tlb_default_mem;
+ * not be bounced (unless SWIOTLB_FORCE is set).
+ */
+ static unsigned int max_segment;
++static unsigned char *swiotlb_bounce_remap_addr;
+
+ static unsigned long default_nslabs = IO_TLB_DEFAULT_SIZE >> IO_TLB_SHIFT;
+
+@@ -334,6 +335,11 @@ void __init swiotlb_exit(void)
+ io_tlb_default_mem = NULL;
+ }
+
++void swiotlb_set_bounce_remap(unsigned char *vaddr)
+{
-+ vunmap((void *)addr);
-+}
-diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
-index fe03e3e833ac..ba3cb9e32fdb 100644
---- a/arch/x86/include/asm/mshyperv.h
-+++ b/arch/x86/include/asm/mshyperv.h
-@@ -253,6 +253,8 @@ int hv_map_ioapic_interrupt(int ioapic_id, bool level, int vcpu, int vector,
- int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry);
- int hv_mark_gpa_visibility(u16 count, const u64 pfn[], u32 visibility);
- int hv_set_mem_enc(unsigned long addr, int numpages, bool enc);
-+unsigned long hv_map_memory(unsigned long addr, unsigned long size);
-+void hv_unmap_memory(unsigned long addr);
- void hv_sint_wrmsrl_ghcb(u64 msr, u64 value);
- void hv_sint_rdmsrl_ghcb(u64 msr, u64 *value);
- void hv_signal_eom_ghcb(void);
-diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
-index 43fa081a1adb..7a2117931830 100644
---- a/arch/x86/include/asm/set_memory.h
-+++ b/arch/x86/include/asm/set_memory.h
-@@ -49,6 +49,8 @@ int set_memory_decrypted(unsigned long addr, int numpages);
- int set_memory_np_noalias(unsigned long addr, int numpages);
- int set_memory_nonglobal(unsigned long addr, int numpages);
- int set_memory_global(unsigned long addr, int numpages);
-+unsigned long set_memory_decrypted_map(unsigned long addr, unsigned long size);
-+int set_memory_encrypted_unmap(unsigned long addr, unsigned long size);
-
- int set_pages_array_uc(struct page **pages, int addrinarray);
- int set_pages_array_wc(struct page **pages, int addrinarray);
-diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
-index 6cc83c57383d..5d4d3963f4a2 100644
---- a/arch/x86/mm/pat/set_memory.c
-+++ b/arch/x86/mm/pat/set_memory.c
-@@ -2039,6 +2039,34 @@ int set_memory_decrypted(unsigned long addr, int numpages)
- }
- EXPORT_SYMBOL_GPL(set_memory_decrypted);
-
-+static unsigned long __map_memory(unsigned long addr, unsigned long size)
-+{
-+ if (hv_is_isolation_supported())
-+ return hv_map_memory(addr, size);
-+
-+ return addr;
++ swiotlb_bounce_remap_addr = vaddr;
+}
+
-+static void __unmap_memory(unsigned long addr)
-+{
-+ if (hv_is_isolation_supported())
-+ hv_unmap_memory(addr);
-+}
-+
-+unsigned long set_memory_decrypted_map(unsigned long addr, unsigned long size)
-+{
-+ if (__set_memory_enc_dec(addr, size / PAGE_SIZE, false))
-+ return (unsigned long)NULL;
-+
-+ return __map_memory(addr, size);
-+}
-+
-+int set_memory_encrypted_unmap(unsigned long addr, unsigned long size)
-+{
-+ __unmap_memory(addr);
-+ return __set_memory_enc_dec(addr, size / PAGE_SIZE, true);
-+}
-+
- int set_pages_uc(struct page *page, int numpages)
- {
- unsigned long addr = (unsigned long)page_address(page);
-diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
-index f507e3eacbea..5c6f6c7380ef 100644
---- a/include/linux/swiotlb.h
-+++ b/include/linux/swiotlb.h
-@@ -72,6 +72,9 @@ extern enum swiotlb_force swiotlb_force;
- * @end: The end address of the swiotlb memory pool. Used to do a quick
- * range check to see if the memory was in fact allocated by this
- * API.
-+ * @vstart: The virtual start address of the swiotlb memory pool. The swiotlb
-+ * memory pool may be remapped in the memory encrypted case and store
-+ * virtual address for bounce buffer operation.
- * @nslabs: The number of IO TLB blocks (in groups of 64) between @start and
- * @end. For default swiotlb, this is command line adjustable via
- * setup_io_tlb_npages.
-@@ -89,6 +92,7 @@ extern enum swiotlb_force swiotlb_force;
- struct io_tlb_mem {
- phys_addr_t start;
- phys_addr_t end;
-+ void *vstart;
- unsigned long nslabs;
- unsigned long used;
- unsigned int index;
-diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
-index d3fa4669229b..9911817250a8 100644
---- a/kernel/dma/swiotlb.c
-+++ b/kernel/dma/swiotlb.c
-@@ -194,8 +194,13 @@ static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start,
- mem->slots[i].alloc_size = 0;
- }
-
-- set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
-- memset(vaddr, 0, bytes);
-+ mem->vstart = (void *)set_memory_decrypted_map((unsigned long)vaddr, bytes);
-+ if (!mem->vstart) {
-+ pr_err("Failed to decrypt memory.\n");
-+ return;
-+ }
-+
-+ memset(mem->vstart, 0, bytes);
- }
-
- int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
-@@ -352,7 +357,7 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size
+ /*
+ * Bounce: copy the swiotlb buffer from or back to the original dma location
+ */
+@@ -345,7 +351,13 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size
phys_addr_t orig_addr = mem->slots[index].orig_addr;
size_t alloc_size = mem->slots[index].alloc_size;
unsigned long pfn = PFN_DOWN(orig_addr);
- unsigned char *vaddr = phys_to_virt(tlb_addr);
-+ unsigned char *vaddr = mem->vstart + tlb_addr - mem->start;
++ unsigned char *vaddr;
++
++ if (swiotlb_bounce_remap_addr)
++ vaddr = swiotlb_bounce_remap_addr + tlb_addr -
++ io_tlb_default_mem->start;
++ else
++ vaddr = phys_to_virt(tlb_addr);
if (orig_addr == INVALID_PHYS_ADDR)
return;