From: Will Deacon Date: Tue, 23 May 2023 10:18:21 +0000 (+0100) Subject: KVM: arm64: Handle FFA_RXTX_MAP and FFA_RXTX_UNMAP calls from the host X-Git-Tag: v6.6.7~2444^2~7^2~6^2~6 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9d0c6a9af9e38efa675e565bd181794deca1188a;p=platform%2Fkernel%2Flinux-starfive.git KVM: arm64: Handle FFA_RXTX_MAP and FFA_RXTX_UNMAP calls from the host Handle FFA_RXTX_MAP and FFA_RXTX_UNMAP calls from the host by sharing the host's mailbox memory with the hypervisor and establishing a separate pair of mailboxes between the hypervisor and the SPMD at EL3. Co-developed-by: Andrew Walbran Signed-off-by: Andrew Walbran Signed-off-by: Will Deacon Link: https://lore.kernel.org/r/20230523101828.7328-5-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 c85e5d4..0c020cd 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -31,6 +31,8 @@ #include #include +#include +#include #include #include @@ -52,6 +54,7 @@ struct kvm_ffa_buffers { * client. */ static struct kvm_ffa_buffers hyp_buffers; +static struct kvm_ffa_buffers host_buffers; static void ffa_to_smccc_error(struct arm_smccc_res *res, u64 ffa_errno) { @@ -61,6 +64,15 @@ static void ffa_to_smccc_error(struct arm_smccc_res *res, u64 ffa_errno) }; } +static void ffa_to_smccc_res(struct arm_smccc_res *res, int ret) +{ + if (ret == FFA_RET_SUCCESS) { + *res = (struct arm_smccc_res) { .a0 = FFA_SUCCESS }; + } else { + ffa_to_smccc_error(res, ret); + } +} + static void ffa_set_retval(struct kvm_cpu_context *ctxt, struct arm_smccc_res *res) { @@ -78,6 +90,144 @@ static bool is_ffa_call(u64 func_id) ARM_SMCCC_FUNC_NUM(func_id) <= FFA_MAX_FUNC_NUM; } +static int ffa_map_hyp_buffers(u64 ffa_page_count) +{ + struct arm_smccc_res res; + + arm_smccc_1_1_smc(FFA_FN64_RXTX_MAP, + hyp_virt_to_phys(hyp_buffers.tx), + hyp_virt_to_phys(hyp_buffers.rx), + ffa_page_count, + 0, 0, 0, 0, + &res); + + return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2; +} + +static int ffa_unmap_hyp_buffers(void) +{ + struct arm_smccc_res res; + + arm_smccc_1_1_smc(FFA_RXTX_UNMAP, + HOST_FFA_ID, + 0, 0, 0, 0, 0, 0, + &res); + + return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2; +} + +static void do_ffa_rxtx_map(struct arm_smccc_res *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(phys_addr_t, tx, ctxt, 1); + DECLARE_REG(phys_addr_t, rx, ctxt, 2); + DECLARE_REG(u32, npages, ctxt, 3); + int ret = 0; + void *rx_virt, *tx_virt; + + if (npages != (KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) / FFA_PAGE_SIZE) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + + if (!PAGE_ALIGNED(tx) || !PAGE_ALIGNED(rx)) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + + hyp_spin_lock(&host_buffers.lock); + if (host_buffers.tx) { + ret = FFA_RET_DENIED; + goto out_unlock; + } + + /* + * Map our hypervisor buffers into the SPMD before mapping and + * pinning the host buffers in our own address space. + */ + ret = ffa_map_hyp_buffers(npages); + if (ret) + goto out_unlock; + + ret = __pkvm_host_share_hyp(hyp_phys_to_pfn(tx)); + if (ret) { + ret = FFA_RET_INVALID_PARAMETERS; + goto err_unmap; + } + + ret = __pkvm_host_share_hyp(hyp_phys_to_pfn(rx)); + if (ret) { + ret = FFA_RET_INVALID_PARAMETERS; + goto err_unshare_tx; + } + + tx_virt = hyp_phys_to_virt(tx); + ret = hyp_pin_shared_mem(tx_virt, tx_virt + 1); + if (ret) { + ret = FFA_RET_INVALID_PARAMETERS; + goto err_unshare_rx; + } + + rx_virt = hyp_phys_to_virt(rx); + ret = hyp_pin_shared_mem(rx_virt, rx_virt + 1); + if (ret) { + ret = FFA_RET_INVALID_PARAMETERS; + goto err_unpin_tx; + } + + host_buffers.tx = tx_virt; + host_buffers.rx = rx_virt; + +out_unlock: + hyp_spin_unlock(&host_buffers.lock); +out: + ffa_to_smccc_res(res, ret); + return; + +err_unpin_tx: + hyp_unpin_shared_mem(tx_virt, tx_virt + 1); +err_unshare_rx: + __pkvm_host_unshare_hyp(hyp_phys_to_pfn(rx)); +err_unshare_tx: + __pkvm_host_unshare_hyp(hyp_phys_to_pfn(tx)); +err_unmap: + ffa_unmap_hyp_buffers(); + goto out_unlock; +} + +static void do_ffa_rxtx_unmap(struct arm_smccc_res *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(u32, id, ctxt, 1); + int ret = 0; + + if (id != HOST_FFA_ID) { + 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; + } + + hyp_unpin_shared_mem(host_buffers.tx, host_buffers.tx + 1); + WARN_ON(__pkvm_host_unshare_hyp(hyp_virt_to_pfn(host_buffers.tx))); + host_buffers.tx = NULL; + + hyp_unpin_shared_mem(host_buffers.rx, host_buffers.rx + 1); + WARN_ON(__pkvm_host_unshare_hyp(hyp_virt_to_pfn(host_buffers.rx))); + host_buffers.rx = NULL; + + ffa_unmap_hyp_buffers(); + +out_unlock: + hyp_spin_unlock(&host_buffers.lock); +out: + ffa_to_smccc_res(res, ret); +} + /* * Is a given FFA function supported, either by forwarding on directly * or by handling at EL2? @@ -132,10 +282,21 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt) if (!is_ffa_call(func_id)) return false; + switch (func_id) { + /* Memory management */ + case FFA_FN64_RXTX_MAP: + do_ffa_rxtx_map(&res, host_ctxt); + goto out_handled; + case FFA_RXTX_UNMAP: + do_ffa_rxtx_unmap(&res, host_ctxt); + goto out_handled; + } + if (ffa_call_supported(func_id)) return false; /* Pass through */ ffa_to_smccc_error(&res, FFA_RET_NOT_SUPPORTED); +out_handled: ffa_set_retval(host_ctxt, &res); return true; } @@ -143,6 +304,7 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt) int hyp_ffa_init(void *pages) { struct arm_smccc_res res; + size_t min_rxtx_sz; if (kvm_host_psci_config.smccc_version < ARM_SMCCC_VERSION_1_2) return 0; @@ -161,11 +323,37 @@ int hyp_ffa_init(void *pages) if (res.a2 != HOST_FFA_ID) return -EINVAL; + arm_smccc_1_1_smc(FFA_FEATURES, FFA_FN64_RXTX_MAP, + 0, 0, 0, 0, 0, 0, &res); + if (res.a0 != FFA_SUCCESS) + return -EOPNOTSUPP; + + switch (res.a2) { + case FFA_FEAT_RXTX_MIN_SZ_4K: + min_rxtx_sz = SZ_4K; + break; + case FFA_FEAT_RXTX_MIN_SZ_16K: + min_rxtx_sz = SZ_16K; + break; + case FFA_FEAT_RXTX_MIN_SZ_64K: + min_rxtx_sz = SZ_64K; + break; + default: + return -EINVAL; + } + + if (min_rxtx_sz > PAGE_SIZE) + return -EOPNOTSUPP; + hyp_buffers = (struct kvm_ffa_buffers) { .lock = __HYP_SPIN_LOCK_UNLOCKED, .tx = pages, .rx = pages + (KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE), }; + host_buffers = (struct kvm_ffa_buffers) { + .lock = __HYP_SPIN_LOCK_UNLOCKED, + }; + return 0; } diff --git a/include/linux/arm_ffa.h b/include/linux/arm_ffa.h index c87aeec..b9f8103 100644 --- a/include/linux/arm_ffa.h +++ b/include/linux/arm_ffa.h @@ -94,6 +94,14 @@ */ #define FFA_PAGE_SIZE SZ_4K +/* + * Minimum buffer size/alignment encodings returned by an FFA_FEATURES + * query for FFA_RXTX_MAP. + */ +#define FFA_FEAT_RXTX_MIN_SZ_4K 0 +#define FFA_FEAT_RXTX_MIN_SZ_64K 1 +#define FFA_FEAT_RXTX_MIN_SZ_16K 2 + /* FFA Bus/Device/Driver related */ struct ffa_device { int vm_id;