From: Tianyu Lan <ltykernel@xxxxxxxxx> Sent: Saturday, January 21, 2023 6:46 PM
>
As I comment on v2 of this patch, the Subject prefix should be
"Drivers: hv: vmbus:"
> Vmbus post msg, synic event and message pages are shared
s/Vmbus/VMBus/
We're trying to be consistent about the capitalization of "VMBus"
in comments and other text. :-)
> with hypervisor and so decrypt these pages in the sev-snp guest.
>
> Signed-off-by: Tianyu Lan <tiala@xxxxxxxxxxxxx>
> ---
> Change since RFC V2:
> * Fix error in the error code path and encrypt
> pages correctly when decryption failure happens.
> ---
> drivers/hv/hv.c | 33 ++++++++++++++++++++++++++++++++-
> 1 file changed, 32 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
> index 410e6c4e80d3..52edc54c8172 100644
> --- a/drivers/hv/hv.c
> +++ b/drivers/hv/hv.c
> @@ -20,6 +20,7 @@
> #include <linux/interrupt.h>
> #include <clocksource/hyperv_timer.h>
> #include <asm/mshyperv.h>
> +#include <linux/set_memory.h>
> #include "hyperv_vmbus.h"
>
> /* The one and only */
> @@ -117,7 +118,7 @@ int hv_post_message(union hv_connection_id connection_id,
>
> int hv_synic_alloc(void)
> {
> - int cpu;
> + int cpu, ret;
> struct hv_per_cpu_context *hv_cpu;
>
> /*
> @@ -168,9 +169,39 @@ int hv_synic_alloc(void)
> pr_err("Unable to allocate post msg page\n");
> goto err;
> }
> +
> + if (hv_isolation_type_en_snp()) {
> + ret = set_memory_decrypted((unsigned long)
> + hv_cpu->synic_message_page, 1);
> + if (ret)
> + goto err;
> +
> + ret = set_memory_decrypted((unsigned long)
> + hv_cpu->synic_event_page, 1);
> + if (ret)
> + goto err_decrypt_event_page;
> +
> + ret = set_memory_decrypted((unsigned long)
> + hv_cpu->post_msg_page, 1);
> + if (ret)
> + goto err_decrypt_msg_page;
> +
> + memset(hv_cpu->synic_message_page, 0, PAGE_SIZE);
> + memset(hv_cpu->synic_event_page, 0, PAGE_SIZE);
> + memset(hv_cpu->post_msg_page, 0, PAGE_SIZE);
> + }
Having decrypted the pages here in hv_synic_alloc(), shouldn't
there be corresponding re-encryption in hv_synic_free()?
> }
>
> return 0;
> +
> +err_decrypt_msg_page:
> + set_memory_encrypted((unsigned long)
> + hv_cpu->synic_event_page, 1);
> +
> +err_decrypt_event_page:
> + set_memory_encrypted((unsigned long)
> + hv_cpu->synic_message_page, 1);
> +
> err:
> /*
> * Any memory allocations that succeeded will be freed when
> --
> 2.25.1
