From: Will Deacon Date: Tue, 23 May 2023 10:18:23 +0000 (+0100) Subject: KVM: arm64: Handle FFA_MEM_SHARE calls from the host X-Git-Tag: v6.6.7~2444^2~7^2~6^2~4 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=43609000177625b1c93c55a16a07aee5a4258260;p=platform%2Fkernel%2Flinux-starfive.git KVM: arm64: Handle FFA_MEM_SHARE calls from the host Intercept FFA_MEM_SHARE/FFA_FN64_MEM_SHARE calls from the host and transition the host stage-2 page-table entries from the OWNED state to the SHARED_OWNED state prior to forwarding the call onto EL3. Co-developed-by: Andrew Walbran Signed-off-by: Andrew Walbran Signed-off-by: Will Deacon Link: https://lore.kernel.org/r/20230523101828.7328-7-will@kernel.org Signed-off-by: Oliver Upton --- diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index 0c020cd..83c41c0 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -116,6 +116,14 @@ static int ffa_unmap_hyp_buffers(void) return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2; } +static void ffa_mem_share(struct arm_smccc_res *res, u32 len, u32 fraglen) +{ + arm_smccc_1_1_smc(FFA_FN64_MEM_SHARE, + len, fraglen, + 0, 0, 0, 0, 0, + res); +} + static void do_ffa_rxtx_map(struct arm_smccc_res *res, struct kvm_cpu_context *ctxt) { @@ -228,6 +236,149 @@ out: ffa_to_smccc_res(res, ret); } +static u32 __ffa_host_share_ranges(struct ffa_mem_region_addr_range *ranges, + u32 nranges) +{ + u32 i; + + for (i = 0; i < nranges; ++i) { + struct ffa_mem_region_addr_range *range = &ranges[i]; + u64 sz = (u64)range->pg_cnt * FFA_PAGE_SIZE; + u64 pfn = hyp_phys_to_pfn(range->address); + + if (!PAGE_ALIGNED(sz)) + break; + + if (__pkvm_host_share_ffa(pfn, sz / PAGE_SIZE)) + break; + } + + return i; +} + +static u32 __ffa_host_unshare_ranges(struct ffa_mem_region_addr_range *ranges, + u32 nranges) +{ + u32 i; + + for (i = 0; i < nranges; ++i) { + struct ffa_mem_region_addr_range *range = &ranges[i]; + u64 sz = (u64)range->pg_cnt * FFA_PAGE_SIZE; + u64 pfn = hyp_phys_to_pfn(range->address); + + if (!PAGE_ALIGNED(sz)) + break; + + if (__pkvm_host_unshare_ffa(pfn, sz / PAGE_SIZE)) + break; + } + + return i; +} + +static int ffa_host_share_ranges(struct ffa_mem_region_addr_range *ranges, + u32 nranges) +{ + u32 nshared = __ffa_host_share_ranges(ranges, nranges); + int ret = 0; + + if (nshared != nranges) { + WARN_ON(__ffa_host_unshare_ranges(ranges, nshared) != nshared); + ret = FFA_RET_DENIED; + } + + return ret; +} + +static int ffa_host_unshare_ranges(struct ffa_mem_region_addr_range *ranges, + u32 nranges) +{ + u32 nunshared = __ffa_host_unshare_ranges(ranges, nranges); + int ret = 0; + + if (nunshared != nranges) { + WARN_ON(__ffa_host_share_ranges(ranges, nunshared) != nunshared); + ret = FFA_RET_DENIED; + } + + return ret; +} + +static void do_ffa_mem_share(struct arm_smccc_res *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(u32, len, ctxt, 1); + DECLARE_REG(u32, fraglen, ctxt, 2); + DECLARE_REG(u64, addr_mbz, ctxt, 3); + DECLARE_REG(u32, npages_mbz, ctxt, 4); + struct ffa_composite_mem_region *reg; + struct ffa_mem_region *buf; + int ret = 0; + u32 offset; + + if (addr_mbz || npages_mbz || fraglen > len || + fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + + if (fraglen < len) { + ret = FFA_RET_ABORTED; + goto out; + } + + if (fraglen < sizeof(struct ffa_mem_region) + + sizeof(struct ffa_mem_region_attributes)) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + + hyp_spin_lock(&host_buffers.lock); + if (!host_buffers.tx) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + buf = hyp_buffers.tx; + memcpy(buf, host_buffers.tx, fraglen); + + offset = buf->ep_mem_access[0].composite_off; + if (!offset || buf->ep_count != 1 || buf->sender_id != HOST_FFA_ID) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + if (fraglen < offset + sizeof(struct ffa_composite_mem_region)) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + reg = (void *)buf + offset; + if (fraglen < offset + sizeof(struct ffa_composite_mem_region) + + reg->addr_range_cnt * + sizeof(struct ffa_mem_region_addr_range)) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + ret = ffa_host_share_ranges(reg->constituents, reg->addr_range_cnt); + if (ret) + goto out_unlock; + + ffa_mem_share(res, len, fraglen); + if (res->a0 != FFA_SUCCESS) { + WARN_ON(ffa_host_unshare_ranges(reg->constituents, + reg->addr_range_cnt)); + } + +out_unlock: + hyp_spin_unlock(&host_buffers.lock); +out: + if (ret) + ffa_to_smccc_res(res, ret); + return; +} + /* * Is a given FFA function supported, either by forwarding on directly * or by handling at EL2? @@ -290,6 +441,10 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt) case FFA_RXTX_UNMAP: do_ffa_rxtx_unmap(&res, host_ctxt); goto out_handled; + case FFA_MEM_SHARE: + case FFA_FN64_MEM_SHARE: + do_ffa_mem_share(&res, host_ctxt); + goto out_handled; } if (ffa_call_supported(func_id))