On Thu, Dec 22, 2016 at 12:13:12PM +1100, Alexey Kardashevskiy wrote:
> KVM_CAP_SPAPR_TCE capability allows creating TCE tables in KVM which
> allows having in-kernel acceleration for H_PUT_TCE_xxx hypercalls.
> However it only supports 32bit DMA windows at zero bus offset.
>
> There is a new KVM_CAP_SPAPR_TCE_64 capability which supports 64bit
> window size, variable page size and bus offset.
>
> This makes use of the new capability. The kernel headers are already
> updated as the kernel support went in to v4.6.
>
> Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
> ---
> target-ppc/kvm_ppc.h | 12 +++++++-----
> hw/ppc/spapr_iommu.c | 8 +++++---
> target-ppc/kvm.c | 48 +++++++++++++++++++++++++++++++++++++-----------
> 3 files changed, 49 insertions(+), 19 deletions(-)
>
> diff --git a/target-ppc/kvm_ppc.h b/target-ppc/kvm_ppc.h
> index bd1d78bfbe..14320c2378 100644
> --- a/target-ppc/kvm_ppc.h
> +++ b/target-ppc/kvm_ppc.h
> @@ -36,8 +36,9 @@ int kvmppc_booke_watchdog_enable(PowerPCCPU *cpu);
> #ifndef CONFIG_USER_ONLY
> off_t kvmppc_alloc_rma(void **rma);
> bool kvmppc_spapr_use_multitce(void);
> -void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t window_size, int *pfd,
> - bool need_vfio);
> +void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t page_shift,
> + uint64_t bus_offset, uint32_t nb_table,
> + int *pfd, bool need_vfio);
> int kvmppc_remove_spapr_tce(void *table, int pfd, uint32_t window_size);
> int kvmppc_reset_htab(int shift_hint);
> uint64_t kvmppc_rma_size(uint64_t current_size, unsigned int hash_shift);
> @@ -168,9 +169,10 @@ static inline bool kvmppc_spapr_use_multitce(void)
> return false;
> }
>
> -static inline void *kvmppc_create_spapr_tce(uint32_t liobn,
> - uint32_t window_size, int *fd,
> - bool need_vfio)
> +static inline void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t
> page_shift,
> + uint64_t bus_offset,
> + uint32_t nb_table,
> + int *pfd, bool need_vfio)
> {
> return NULL;
> }
> diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c
> index ae30bbe30f..29c80bb3c8 100644
> --- a/hw/ppc/spapr_iommu.c
> +++ b/hw/ppc/spapr_iommu.c
> @@ -79,15 +79,16 @@ static IOMMUAccessFlags
> spapr_tce_iommu_access_flags(uint64_t tce)
>
> static uint64_t *spapr_tce_alloc_table(uint32_t liobn,
> uint32_t page_shift,
> + uint64_t bus_offset,
> uint32_t nb_table,
> int *fd,
> bool need_vfio)
> {
> uint64_t *table = NULL;
> - uint64_t window_size = (uint64_t)nb_table << page_shift;
>
> - if (kvm_enabled() && !(window_size >> 32)) {
> - table = kvmppc_create_spapr_tce(liobn, window_size, fd, need_vfio);
> + if (kvm_enabled()) {
This is broken. Previously, if we had a >4GiB window, we'd fall back
to managing it in userspace, which would work, albeit slowly. Now, if
you have an older kernel which doesn't support KVM_CAP_SPAPR_TCE_64 it
will attempt to allocate it in the kernel, and fail completely.
> + table = kvmppc_create_spapr_tce(liobn, page_shift, bus_offset,
> nb_table,
> + fd, need_vfio);
> }
>
> if (!table) {
> @@ -342,6 +343,7 @@ void spapr_tce_table_enable(sPAPRTCETable *tcet,
> tcet->nb_table = nb_table;
> tcet->table = spapr_tce_alloc_table(tcet->liobn,
> tcet->page_shift,
> + tcet->bus_offset,
> tcet->nb_table,
> &tcet->fd,
> tcet->need_vfio);
> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> index 9c4834c4fc..6e91a4d8bb 100644
> --- a/target-ppc/kvm.c
> +++ b/target-ppc/kvm.c
> @@ -71,6 +71,7 @@ static int cap_booke_sregs;
> static int cap_ppc_smt;
> static int cap_ppc_rma;
> static int cap_spapr_tce;
> +static int cap_spapr_tce_64;
> static int cap_spapr_multitce;
> static int cap_spapr_vfio;
> static int cap_hior;
> @@ -123,6 +124,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
> cap_ppc_smt = kvm_check_extension(s, KVM_CAP_PPC_SMT);
> cap_ppc_rma = kvm_check_extension(s, KVM_CAP_PPC_RMA);
> cap_spapr_tce = kvm_check_extension(s, KVM_CAP_SPAPR_TCE);
> + cap_spapr_tce_64 = kvm_check_extension(s, KVM_CAP_SPAPR_TCE_64);
> cap_spapr_multitce = kvm_check_extension(s, KVM_CAP_SPAPR_MULTITCE);
> cap_spapr_vfio = false;
> cap_one_reg = kvm_check_extension(s, KVM_CAP_ONE_REG);
> @@ -2201,13 +2203,10 @@ bool kvmppc_spapr_use_multitce(void)
> return cap_spapr_multitce;
> }
>
> -void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t window_size, int *pfd,
> - bool need_vfio)
> +void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t page_shift,
> + uint64_t bus_offset, uint32_t nb_table,
> + int *pfd, bool need_vfio)
> {
> - struct kvm_create_spapr_tce args = {
> - .liobn = liobn,
> - .window_size = window_size,
> - };
> long len;
> int fd;
> void *table;
> @@ -2220,14 +2219,41 @@ void *kvmppc_create_spapr_tce(uint32_t liobn,
> uint32_t window_size, int *pfd,
> return NULL;
> }
>
> - fd = kvm_vm_ioctl(kvm_state, KVM_CREATE_SPAPR_TCE, &args);
> - if (fd < 0) {
> - fprintf(stderr, "KVM: Failed to create TCE table for liobn 0x%x\n",
> - liobn);
> + if (cap_spapr_tce_64) {
> + struct kvm_create_spapr_tce_64 args = {
> + .liobn = liobn,
> + .page_shift = page_shift,
> + .offset = bus_offset >> page_shift,
> + .size = nb_table,
> + .flags = 0
> + };
> + fd = kvm_vm_ioctl(kvm_state, KVM_CREATE_SPAPR_TCE_64, &args);
> + if (fd < 0) {
> + fprintf(stderr,
> + "KVM: Failed to create TCE64 table for liobn 0x%x\n",
> + liobn);
> + return NULL;
> + }
> + } else if (cap_spapr_tce) {
> + uint64_t window_size = (uint64_t) nb_table << page_shift;
> + struct kvm_create_spapr_tce args = {
> + .liobn = liobn,
> + .window_size = window_size,
> + };
> + if ((window_size != args.window_size) || bus_offset) {
> + return NULL;
> + }
> + fd = kvm_vm_ioctl(kvm_state, KVM_CREATE_SPAPR_TCE, &args);
> + if (fd < 0) {
> + fprintf(stderr, "KVM: Failed to create TCE table for liobn
> 0x%x\n",
> + liobn);
> + return NULL;
> + }
> + } else {
> return NULL;
> }
>
> - len = (window_size / SPAPR_TCE_PAGE_SIZE) * sizeof(uint64_t);
> + len = nb_table * sizeof(uint64_t);
> /* FIXME: round this up to page size */
>
> table = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
signature.asc
Description: PGP signature
