Re: [Qemu-devel] [PATCH v2 8/9] tpm-passthrough: move reusable code to utils

[Stefan Berger <stefanb@linux.vnet.ibm.com>]

On 04/07/2017 10:30 AM, Amarnath Valluri wrote:
> Signed-off-by: Amarnath Valluri <amarnath.valluri@intel.com>
> ---
>   hw/tpm/tpm_passthrough.c | 64 ++++--------------------------------------------
>   hw/tpm/tpm_util.c        | 25 +++++++++++++++++++
>   hw/tpm/tpm_util.h        |  4 +++
>   3 files changed, 34 insertions(+), 59 deletions(-)
>
> diff --git a/hw/tpm/tpm_passthrough.c b/hw/tpm/tpm_passthrough.c
> index 1bffb6d..ca7c8bb 100644
> --- a/hw/tpm/tpm_passthrough.c
> +++ b/hw/tpm/tpm_passthrough.c
> @@ -68,27 +68,6 @@ 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;
> -}
> -
>   static int tpm_passthrough_unix_read(int fd, uint8_t *buf, uint32_t len)
>   {
>       int ret;
> @@ -102,45 +81,12 @@ static int tpm_passthrough_unix_read(int fd, uint8_t *buf, uint32_t len)
>       }
>       return ret;
>   }
> -
> -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,
>                                           bool *selftest_done)
>   {
> -    int ret;
> +    ssize_t ret;
>       bool is_selftest;
>       const struct tpm_resp_hdr *hdr;
>
> @@ -148,9 +94,9 @@ 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 = qemu_write_full(tpm_pt->tpm_fd, (const void *)in, (size_t)in_len);
>       if (ret != in_len) {
>           if (!tpm_pt->tpm_op_canceled || errno != ECANCELED) {
>               error_report("tpm_passthrough: error while transmitting data "
> @@ -170,7 +116,7 @@ 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) {


Looks like you are missing the be32_to_cpu from above removal.

-    return be32_to_cpu(resp->len);



>           ret = -1;
>           error_report("tpm_passthrough: received invalid response "
>                        "packet from TPM");
> @@ -183,7 +129,7 @@ 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..fb929f6 100644
> --- a/hw/tpm/tpm_util.c
> +++ b/hw/tpm/tpm_util.c
> @@ -24,6 +24,31 @@
>   #include "tpm_int.h"
>
>   /*
> + * 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..2f7c961 100644
> --- a/hw/tpm/tpm_util.h
> +++ b/hw/tpm/tpm_util.h
> @@ -24,6 +24,10 @@
>
>   #include "sysemu/tpm_backend.h"
>
> +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 */