Gerd Hoffmann <[email protected]> writes:
> Allow limiting the amount of log output sent. Allow up to 1 MiB.
> In case the guest log buffer is larger than 1 MiB limit the output
> instead of throwing an error.
>
> Signed-off-by: Gerd Hoffmann <[email protected]>
> ---
> hw/uefi/ovmf-log.c | 42 ++++++++++++++++++++++++++++++++++--------
> hmp-commands-info.hx | 4 ++--
> qapi/machine.json | 5 +++++
> 3 files changed, 41 insertions(+), 10 deletions(-)
>
> diff --git a/hw/uefi/ovmf-log.c b/hw/uefi/ovmf-log.c
> index e281a980a101..28788620e3f6 100644
> --- a/hw/uefi/ovmf-log.c
> +++ b/hw/uefi/ovmf-log.c
> @@ -18,6 +18,7 @@
> #include "qapi/error.h"
> #include "qapi/type-helpers.h"
> #include "qapi/qapi-commands-machine.h"
> +#include "qobject/qdict.h"
>
>
> /* ----------------------------------------------------------------------- */
> @@ -164,7 +165,8 @@ static void handle_ovmf_log_range(GString *out,
> }
> }
>
> -FirmwareLog *qmp_query_firmware_log(Error **errp)
> +FirmwareLog *qmp_query_firmware_log(bool have_max_size, uint64_t max_size,
> + Error **errp)
> {
> MEM_DEBUG_LOG_HDR header;
> dma_addr_t offset, base;
> @@ -184,18 +186,40 @@ FirmwareLog *qmp_query_firmware_log(Error **errp)
> return NULL;
> }
>
> - if (header.DebugLogSize > MiB) {
> - /* default size is 128k (32 pages), allow up to 1M */
> - error_setg(errp, "firmware log: log buffer is too big");
> - return NULL;
> - }
> -
> if (header.DebugLogHeadOffset > header.DebugLogSize ||
> header.DebugLogTailOffset > header.DebugLogSize) {
> error_setg(errp, "firmware log: invalid header");
> return NULL;
> }
>
> + if (have_max_size) {
> + if (max_size > MiB) {
> + error_setg(errp, "firmware log: max-size larger than 1 MiB");
"parameter 'max-size' exceeds 1MiB" or similar.
> + return NULL;
> + }
> + } else {
> + max_size = MiB;
> + }
> +
> + /* adjust header.DebugLogHeadOffset so we return at most maxsize bytes */
> + if (header.DebugLogHeadOffset > header.DebugLogTailOffset) {
> + /* wrap around */
> + if (header.DebugLogTailOffset > max_size) {
> + header.DebugLogHeadOffset = header.DebugLogTailOffset - max_size;
> + } else {
> + uint64_t max_chunk = max_size - header.DebugLogTailOffset;
> + if (header.DebugLogSize > max_chunk &&
> + header.DebugLogHeadOffset < header.DebugLogSize - max_chunk)
> {
> + header.DebugLogHeadOffset = header.DebugLogSize - max_chunk;
> + }
> + }
> + } else {
> + if (header.DebugLogTailOffset > max_size &&
> + header.DebugLogHeadOffset < header.DebugLogTailOffset -
> max_size) {
> + header.DebugLogHeadOffset = header.DebugLogTailOffset - max_size;
> + }
> + }
Didn't review this part; my brain's fried for today :)
> +
> base = offset + header.HeaderSize;
> if (header.DebugLogHeadOffset > header.DebugLogTailOffset) {
> /* wrap around */
> @@ -239,8 +263,10 @@ void hmp_info_firmware_log(Monitor *mon, const QDict
> *qdict)
> Error *err = NULL;
> FirmwareLog *log;
> gsize log_len;
> + int64_t maxsize;
>
> - log = qmp_query_firmware_log(&err);
> + maxsize = qdict_get_try_int(qdict, "maxsize", -1);
> + log = qmp_query_firmware_log(maxsize != -1, (uint64_t)maxsize, &err);
> if (err) {
> hmp_handle_error(mon, err);
> return;
> diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
> index f0aef419923c..f00d7081b40c 100644
> --- a/hmp-commands-info.hx
> +++ b/hmp-commands-info.hx
> @@ -993,8 +993,8 @@ ERST
>
> {
> .name = "firmware-log",
> - .args_type = "",
> - .params = "",
> + .args_type = "maxsize:o?",
> + .params = "[maxsize]",
> .help = "show the firmware (ovmf) debug log",
> .cmd = hmp_info_firmware_log,
> },
Might want to spell it max-size for consistency with QMP. Up to you.
> diff --git a/qapi/machine.json b/qapi/machine.json
> index 96133e5c71cf..e4b15680c172 100644
> --- a/qapi/machine.json
> +++ b/qapi/machine.json
> @@ -1858,9 +1858,14 @@
> #
> # Find firmware memory log buffer in guest memory, return content.
> #
> +# @max-size: limit the amount of log data returned. Up to 1 MiB if
> +# log data is allowed. In case the amout of log data is
What are you trying to convey by "if log data is allowed"?
s/amout/amount/
> +# larger than max-size the tail of the log is returned.
Please use @max-size here for nicer rendering.
> +#
> # Since: 10.2
> ##
> { 'command': 'query-firmware-log',
> + 'data': { '*max-size': 'size' },
> 'returns': 'FirmwareLog' }
>
> ##
