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Peter Anvin" , linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, kvm@vger.kernel.org, Xiaoyao Li , Binbin Wu References: <20260729122939.1340412-1-peter.fang@intel.com> <20260729122939.1340412-4-peter.fang@intel.com> Content-Language: en-US From: Kuppuswamy Sathyanarayanan In-Reply-To: <20260729122939.1340412-4-peter.fang@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 7/29/2026 5:29 AM, Peter Fang wrote: > In preparation for dynamic Quote buffer sizes, replace the fixed size sizes -> size? > constant with a variable. > > The size is currently a constant sprinkled across several places. Store > it in a variable and have all the users read it from there. You are also dropping PAGE_ALIGN() in alloc and free calls. You can mention it in commit log. > > Signed-off-by: Peter Fang > --- Reviewed-by: Kuppuswamy Sathyanarayanan > v3: > - Split out using a variable for the buffer size from the v2 "Allocate > Quote buffer dynamically" patch to refactor first. [Dave] > - Pass the buffer size into alloc_quote_buf() by value. [Dave] > - Drop the Reviewed-by tags from v2 (Kiryl, Binbin) as the patch was > reworked. > --- > drivers/virt/coco/tdx-guest/tdx-guest.c | 22 +++++++++++----------- > 1 file changed, 11 insertions(+), 11 deletions(-) > > diff --git a/drivers/virt/coco/tdx-guest/tdx-guest.c b/drivers/virt/coco/tdx-guest/tdx-guest.c > index f47c5429d002..3d3f79ab45af 100644 > --- a/drivers/virt/coco/tdx-guest/tdx-guest.c > +++ b/drivers/virt/coco/tdx-guest/tdx-guest.c > @@ -191,8 +191,9 @@ struct tdx_quote_buf { > u8 data[]; > }; > > -/* Quote data buffer */ > +/* Quote data buffer and length */ > static void *quote_data; > +static size_t quote_data_len; > > /* Lock to streamline quote requests */ > static DEFINE_MUTEX(quote_lock); > @@ -209,9 +210,8 @@ static long tdx_get_report0(struct tdx_report_req __user *req) > USER_SOCKPTR(req->tdreport)); > } > > -static void free_quote_buf(void *buf) > +static void free_quote_buf(void *buf, size_t len) > { > - size_t len = PAGE_ALIGN(GET_QUOTE_BUF_SIZE); > unsigned int count = len >> PAGE_SHIFT; > > if (set_memory_encrypted((unsigned long)buf, count)) { > @@ -222,9 +222,8 @@ static void free_quote_buf(void *buf) > free_pages_exact(buf, len); > } > > -static void *alloc_quote_buf(void) > +static void *alloc_quote_buf(size_t len) > { > - size_t len = PAGE_ALIGN(GET_QUOTE_BUF_SIZE); > unsigned int count = len >> PAGE_SHIFT; > void *addr; > > @@ -285,7 +284,7 @@ static int tdx_report_new_locked(struct tsm_report *report, void *data) > if (desc->inblob_len != TDX_REPORTDATA_LEN) > return -EINVAL; > > - memset(quote_data, 0, GET_QUOTE_BUF_SIZE); > + memset(quote_data, 0, quote_data_len); > > /* Update Quote buffer header */ > quote_buf->version = GET_QUOTE_CMD_VER; > @@ -296,7 +295,7 @@ static int tdx_report_new_locked(struct tsm_report *report, void *data) > if (ret) > return ret; > > - err = tdx_hcall_get_quote(quote_data, GET_QUOTE_BUF_SIZE); > + err = tdx_hcall_get_quote(quote_data, quote_data_len); > if (err) { > pr_err("GetQuote hypercall failed, status:%llx\n", err); > return -EIO; > @@ -315,7 +314,7 @@ static int tdx_report_new_locked(struct tsm_report *report, void *data) > > out_len = READ_ONCE(quote_buf->out_len); > > - if (TDX_QUOTE_BUF_LEN(out_len) > GET_QUOTE_BUF_SIZE) > + if (TDX_QUOTE_BUF_LEN(out_len) > quote_data_len) > return -EFBIG; > > buf = kvmemdup(quote_buf->data, out_len, GFP_KERNEL); > @@ -417,7 +416,8 @@ static int __init tdx_guest_init(void) > if (ret) > goto deinit_mr; > > - quote_data = alloc_quote_buf(); > + quote_data_len = GET_QUOTE_BUF_SIZE; > + quote_data = alloc_quote_buf(quote_data_len); > if (!quote_data) { > pr_err("Failed to allocate Quote buffer\n"); > ret = -ENOMEM; > @@ -431,7 +431,7 @@ static int __init tdx_guest_init(void) > return 0; > > free_quote: > - free_quote_buf(quote_data); > + free_quote_buf(quote_data, quote_data_len); > free_misc: > misc_deregister(&tdx_misc_dev); > deinit_mr: > @@ -444,7 +444,7 @@ module_init(tdx_guest_init); > static void __exit tdx_guest_exit(void) > { > tsm_report_unregister(&tdx_tsm_ops); > - free_quote_buf(quote_data); > + free_quote_buf(quote_data, quote_data_len); > misc_deregister(&tdx_misc_dev); > tdx_mr_deinit(tdx_attr_groups[0]); > } -- Sathyanarayanan Kuppuswamy Linux Kernel Developer