Re: [Qemu-devel] [PATCH 6/7] tpm-passthrough: move reusable code to utils

["Marc-André Lureau" <marcandre.lureau@gmail.com>]

Hi

On Fri, Mar 31, 2017 at 4:57 PM Amarnath Valluri <amarnath.valluri@intel.com>
wrote:

> Signed-off-by: Amarnath Valluri <amarnath.valluri@intel.com>
>

Nothing really controversial here. You could point out in the commit
message that those functions will be used in the new backend perhaps.


> ---
>  hw/tpm/tpm_passthrough.c | 77
> ++++--------------------------------------------
>  hw/tpm/tpm_util.c        | 60 +++++++++++++++++++++++++++++++++++++
>  hw/tpm/tpm_util.h        |  8 +++++
>  3 files changed, 73 insertions(+), 72 deletions(-)
>
> diff --git a/hw/tpm/tpm_passthrough.c b/hw/tpm/tpm_passthrough.c
> index fce1163..fc60914 100644
> --- a/hw/tpm/tpm_passthrough.c
> +++ b/hw/tpm/tpm_passthrough.c
> @@ -69,73 +69,6 @@ typedef struct TPMPassthruState TPMPassthruState;
>
>  static void tpm_passthrough_cancel_cmd(TPMBackend *tb);
>
> -static int tpm_passthrough_unix_write(int fd, const uint8_t *buf,
> uint32_t len)
> -{
> -    int ret, remain;
> -
> -    remain = len;
> -    while (remain > 0) {
> -        ret = write(fd, buf, remain);
> -        if (ret < 0) {
> -            if (errno != EINTR && errno != EAGAIN) {
> -                return -1;
> -            }
> -        } else if (ret == 0) {
> -            break;
> -        } else {
> -            buf += ret;
> -            remain -= ret;
> -        }
> -    }
> -    return len - remain;
> -}
>

that looks like qemu_write_full()


> -
> -static int tpm_passthrough_unix_read(int fd, uint8_t *buf, uint32_t len)
> -{
> -    int ret;
> - reread:
> -    ret = read(fd, buf, len);
> -    if (ret < 0) {
> -        if (errno != EINTR && errno != EAGAIN) {
> -            return -1;
> -        }
> -        goto reread;
> -    }
> -    return ret;
> -}
> -
>

Eventually, we may want to switch to QIOChannel.. just some thoughts

-static uint32_t tpm_passthrough_get_size_from_buffer(const uint8_t *buf)
> -{
> -    struct tpm_resp_hdr *resp = (struct tpm_resp_hdr *)buf;
> -
> -    return be32_to_cpu(resp->len);
> -}
> -
> -/*
> - * Write an error message in the given output buffer.
> - */
> -static void tpm_write_fatal_error_response(uint8_t *out, uint32_t out_len)
> -{
> -    if (out_len >= sizeof(struct tpm_resp_hdr)) {
> -        struct tpm_resp_hdr *resp = (struct tpm_resp_hdr *)out;
> -
> -        resp->tag = cpu_to_be16(TPM_TAG_RSP_COMMAND);
> -        resp->len = cpu_to_be32(sizeof(struct tpm_resp_hdr));
> -        resp->errcode = cpu_to_be32(TPM_FAIL);
> -    }
> -}
> -
> -static bool tpm_passthrough_is_selftest(const uint8_t *in, uint32_t
> in_len)
> -{
> -    struct tpm_req_hdr *hdr = (struct tpm_req_hdr *)in;
> -
> -    if (in_len >= sizeof(*hdr)) {
> -        return (be32_to_cpu(hdr->ordinal) == TPM_ORD_ContinueSelfTest);
> -    }
> -
> -    return false;
> -}
> -
>  static int tpm_passthrough_unix_tx_bufs(TPMPassthruState *tpm_pt,
>                                          const uint8_t *in, uint32_t
> in_len,
>                                          uint8_t *out, uint32_t out_len,
> @@ -149,9 +82,9 @@ static int
> tpm_passthrough_unix_tx_bufs(TPMPassthruState *tpm_pt,
>      tpm_pt->tpm_executing = true;
>      *selftest_done = false;
>
> -    is_selftest = tpm_passthrough_is_selftest(in, in_len);
> +    is_selftest = tpm_util_is_selftest(in, in_len);
>
> -    ret = tpm_passthrough_unix_write(tpm_pt->tpm_fd, in, in_len);
> +    ret = tpm_util_unix_write(tpm_pt->tpm_fd, in, in_len);
>      if (ret != in_len) {
>          if (!tpm_pt->tpm_op_canceled || errno != ECANCELED) {
>              error_report("tpm_passthrough: error while transmitting data "
> @@ -163,7 +96,7 @@ static int
> tpm_passthrough_unix_tx_bufs(TPMPassthruState *tpm_pt,
>
>      tpm_pt->tpm_executing = false;
>
> -    ret = tpm_passthrough_unix_read(tpm_pt->tpm_fd, out, out_len);
> +    ret = tpm_util_unix_read(tpm_pt->tpm_fd, out, out_len);
>      if (ret < 0) {
>          if (!tpm_pt->tpm_op_canceled || errno != ECANCELED) {
>              error_report("tpm_passthrough: error while reading data from "
> @@ -171,7 +104,7 @@ static int
> tpm_passthrough_unix_tx_bufs(TPMPassthruState *tpm_pt,
>                           strerror(errno), errno);
>          }
>      } else if (ret < sizeof(struct tpm_resp_hdr) ||
> -               tpm_passthrough_get_size_from_buffer(out) != ret) {
> +               ((struct tpm_resp_hdr *)out)->len != ret) {
>          ret = -1;
>          error_report("tpm_passthrough: received invalid response "
>                       "packet from TPM");
> @@ -184,7 +117,7 @@ static int
> tpm_passthrough_unix_tx_bufs(TPMPassthruState *tpm_pt,
>
>  err_exit:
>      if (ret < 0) {
> -        tpm_write_fatal_error_response(out, out_len);
> +        tpm_util_write_fatal_error_response(out, out_len);
>      }
>
>      tpm_pt->tpm_executing = false;
> diff --git a/hw/tpm/tpm_util.c b/hw/tpm/tpm_util.c
> index 7b35429..5475acf 100644
> --- a/hw/tpm/tpm_util.c
> +++ b/hw/tpm/tpm_util.c
> @@ -23,6 +23,66 @@
>  #include "tpm_util.h"
>  #include "tpm_int.h"
>
> +int tpm_util_unix_write(int fd, const uint8_t *buf, uint32_t len)
> +{
> +    int ret, remain;
> +
> +    remain = len;
> +    while (remain > 0) {
> +        ret = write(fd, buf, remain);
> +        if (ret < 0) {
> +            if (errno != EINTR && errno != EAGAIN) {
> +                return -1;
> +            }
> +        } else if (ret == 0) {
> +            break;
> +        } else {
> +            buf += ret;
> +            remain -= ret;
> +        }
> +    }
> +    return len - remain;
> +}
> +
> +int tpm_util_unix_read(int fd, uint8_t *buf, uint32_t len)
> +{
> +    int ret;
> + reread:
> +    ret = read(fd, buf, len);
> +    if (ret < 0) {
> +        if (errno != EINTR && errno != EAGAIN) {
> +            return -1;
> +        }
> +        goto reread;
> +    }
> +    return ret;
> +}
> +
> +/*
> + * Write an error message in the given output buffer.
> + */
> +void tpm_util_write_fatal_error_response(uint8_t *out, uint32_t out_len)
> +{
> +    if (out_len >= sizeof(struct tpm_resp_hdr)) {
> +        struct tpm_resp_hdr *resp = (struct tpm_resp_hdr *)out;
> +
> +        resp->tag = cpu_to_be16(TPM_TAG_RSP_COMMAND);
> +        resp->len = cpu_to_be32(sizeof(struct tpm_resp_hdr));
> +        resp->errcode = cpu_to_be32(TPM_FAIL);
> +    }
> +}
> +
> +bool tpm_util_is_selftest(const uint8_t *in, uint32_t in_len)
> +{
> +    struct tpm_req_hdr *hdr = (struct tpm_req_hdr *)in;
> +
> +    if (in_len >= sizeof(*hdr)) {
> +        return (be32_to_cpu(hdr->ordinal) == TPM_ORD_ContinueSelfTest);
> +    }
> +
> +    return false;
> +}
> +
>  /*
>   * A basic test of a TPM device. We expect a well formatted response
> header
>   * (error response is fine) within one second.
> diff --git a/hw/tpm/tpm_util.h b/hw/tpm/tpm_util.h
> index df76245..c2feca7 100644
> --- a/hw/tpm/tpm_util.h
> +++ b/hw/tpm/tpm_util.h
> @@ -24,6 +24,14 @@
>
>  #include "sysemu/tpm_backend.h"
>
> +int tpm_util_unix_write(int fd, const uint8_t *buf, uint32_t len);
> +
> +int tpm_util_unix_read(int fd, uint8_t *buf, uint32_t len);
> +
> +void tpm_util_write_fatal_error_response(uint8_t *out, uint32_t out_len);
> +
> +bool tpm_util_is_selftest(const uint8_t *in, uint32_t in_len);
> +
>  int tpm_util_test_tpmdev(int tpm_fd, TPMVersion *tpm_version);
>
>  #endif /* TPM_TPM_UTIL_H */
> --
> 2.7.4
>
>
> --
Marc-André Lureau