From c1135c7fd0e95740cd4619ce389f43ffce043140 Mon Sep 17 00:00:00 2001 From: Boqun Feng Date: Wed, 16 Sep 2020 11:48:09 +0800 Subject: Drivers: hv: vmbus: Introduce types of GPADL This patch introduces two types of GPADL: HV_GPADL_{BUFFER, RING}. The types of GPADL are purely the concept in the guest, IOW the hypervisor treat them as the same. The reason of introducing the types for GPADL is to support guests whose page size is not 4k (the page size of Hyper-V hypervisor). In these guests, both the headers and the data parts of the ringbuffers need to be aligned to the PAGE_SIZE, because 1) some of the ringbuffers will be mapped into userspace and 2) we use "double mapping" mechanism to support fast wrap-around, and "double mapping" relies on ringbuffers being page-aligned. However, the Hyper-V hypervisor only uses 4k (HV_HYP_PAGE_SIZE) headers. Our solution to this is that we always make the headers of ringbuffers take one guest page and when GPADL is established between the guest and hypervisor, the only first 4k of header is used. To handle this special case, we need the types of GPADL to differ different guest memory usage for GPADL. Type enum is introduced along with several general interfaces to describe the differences between normal buffer GPADL and ringbuffer GPADL. Signed-off-by: Boqun Feng Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20200916034817.30282-4-boqun.feng@gmail.com Signed-off-by: Wei Liu --- include/linux/hyperv.h | 48 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 47 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 38100e80360a..9c19149c0e1a 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -29,6 +29,48 @@ #pragma pack(push, 1) +/* + * Types for GPADL, decides is how GPADL header is created. + * + * It doesn't make much difference between BUFFER and RING if PAGE_SIZE is the + * same as HV_HYP_PAGE_SIZE. + * + * If PAGE_SIZE is bigger than HV_HYP_PAGE_SIZE, the headers of ring buffers + * will be of PAGE_SIZE, however, only the first HV_HYP_PAGE will be put + * into gpadl, therefore the number for HV_HYP_PAGE and the indexes of each + * HV_HYP_PAGE will be different between different types of GPADL, for example + * if PAGE_SIZE is 64K: + * + * BUFFER: + * + * gva: |-- 64k --|-- 64k --| ... | + * gpa: | 4k | 4k | ... | 4k | 4k | 4k | ... | 4k | + * index: 0 1 2 15 16 17 18 .. 31 32 ... + * | | ... | | | ... | ... + * v V V V V V + * gpadl: | 4k | 4k | ... | 4k | 4k | 4k | ... | 4k | ... | + * index: 0 1 2 ... 15 16 17 18 .. 31 32 ... + * + * RING: + * + * | header | data | header | data | + * gva: |-- 64k --|-- 64k --| ... |-- 64k --|-- 64k --| ... | + * gpa: | 4k | .. | 4k | 4k | ... | 4k | ... | 4k | .. | 4k | .. | ... | + * index: 0 1 16 17 18 31 ... n n+1 n+16 ... 2n + * | / / / | / / + * | / / / | / / + * | / / ... / ... | / ... / + * | / / / | / / + * | / / / | / / + * V V V V V V v + * gpadl: | 4k | 4k | ... | ... | 4k | 4k | ... | + * index: 0 1 2 ... 16 ... n-15 n-14 n-13 ... 2n-30 + */ +enum hv_gpadl_type { + HV_GPADL_BUFFER, + HV_GPADL_RING +}; + /* Single-page buffer */ struct hv_page_buffer { u32 len; @@ -111,7 +153,7 @@ struct hv_ring_buffer { } feature_bits; /* Pad it to PAGE_SIZE so that data starts on page boundary */ - u8 reserved2[4028]; + u8 reserved2[PAGE_SIZE - 68]; /* * Ring data starts here + RingDataStartOffset @@ -120,6 +162,10 @@ struct hv_ring_buffer { u8 buffer[]; } __packed; +/* Calculate the proper size of a ringbuffer, it must be page-aligned */ +#define VMBUS_RING_SIZE(payload_sz) PAGE_ALIGN(sizeof(struct hv_ring_buffer) + \ + (payload_sz)) + struct hv_ring_buffer_info { struct hv_ring_buffer *ring_buffer; u32 ring_size; /* Include the shared header */ -- cgit v1.2.3 From bca6b91dfdd4347d8fe0bb97377dda0cacd51d82 Mon Sep 17 00:00:00 2001 From: Boqun Feng Date: Wed, 16 Sep 2020 11:48:11 +0800 Subject: Drivers: hv: vmbus: Move virt_to_hvpfn() to hyperv header There will be more places other than vmbus where we need to calculate the Hyper-V page PFN from a virtual address, so move virt_to_hvpfn() to hyperv generic header. Signed-off-by: Boqun Feng Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20200916034817.30282-6-boqun.feng@gmail.com Signed-off-by: Wei Liu --- include/linux/hyperv.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'include/linux') diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 9c19149c0e1a..83456dc181a8 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -14,6 +14,7 @@ #include +#include #include #include #include @@ -23,6 +24,7 @@ #include #include #include +#include #define MAX_PAGE_BUFFER_COUNT 32 #define MAX_MULTIPAGE_BUFFER_COUNT 32 /* 128K */ @@ -1676,4 +1678,17 @@ struct hyperv_pci_block_ops { extern struct hyperv_pci_block_ops hvpci_block_ops; +static inline unsigned long virt_to_hvpfn(void *addr) +{ + phys_addr_t paddr; + + if (is_vmalloc_addr(addr)) + paddr = page_to_phys(vmalloc_to_page(addr)) + + offset_in_page(addr); + else + paddr = __pa(addr); + + return paddr >> HV_HYP_PAGE_SHIFT; +} + #endif /* _HYPERV_H */ -- cgit v1.2.3 From 106dee08408118c5b50387817e74419436e8b651 Mon Sep 17 00:00:00 2001 From: Boqun Feng Date: Wed, 16 Sep 2020 11:48:12 +0800 Subject: hv: hyperv.h: Introduce some hvpfn helper functions When a guest communicate with the hypervisor, it must use HV_HYP_PAGE to calculate PFN, so introduce a few hvpfn helper functions as the counterpart of the page helper functions. This is the preparation for supporting guest whose PAGE_SIZE is not 4k. Signed-off-by: Boqun Feng Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20200916034817.30282-7-boqun.feng@gmail.com Signed-off-by: Wei Liu --- include/linux/hyperv.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux') diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 83456dc181a8..1ce131f29f3b 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1691,4 +1691,9 @@ static inline unsigned long virt_to_hvpfn(void *addr) return paddr >> HV_HYP_PAGE_SHIFT; } +#define NR_HV_HYP_PAGES_IN_PAGE (PAGE_SIZE / HV_HYP_PAGE_SIZE) +#define offset_in_hvpage(ptr) ((unsigned long)(ptr) & ~HV_HYP_PAGE_MASK) +#define HVPFN_UP(x) (((x) + HV_HYP_PAGE_SIZE-1) >> HV_HYP_PAGE_SHIFT) +#define page_to_hvpfn(page) (page_to_pfn(page) * NR_HV_HYP_PAGES_IN_PAGE) + #endif /* _HYPERV_H */ -- cgit v1.2.3