2023-08-10 16:28:20

by Tianyu Lan

Subject: [PATCH V5 6/8] clocksource: hyper-v: Mark hyperv tsc page unencrypted in sev-snp enlightened guest

From: Tianyu Lan <[email protected]>

Hyper-V tsc page is shared with hypervisor and mark the page
unencrypted in sev-snp enlightened guest when it's used.

Reviewed-by: Michael Kelley <[email protected]>
Signed-off-by: Tianyu Lan <[email protected]>
---
drivers/clocksource/hyperv_timer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
index e56307a81f4d..8ff7cd4e20bb 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -390,7 +390,7 @@ static __always_inline u64 read_hv_clock_msr(void)
static union {
struct ms_hyperv_tsc_page page;
u8 reserved[PAGE_SIZE];
-} tsc_pg __aligned(PAGE_SIZE);
+} tsc_pg __bss_decrypted __aligned(PAGE_SIZE);

static struct ms_hyperv_tsc_page *tsc_page = &tsc_pg.page;
static unsigned long tsc_pfn;
--
2.25.1

2023-08-11 00:58:39

by Dexuan Cui

Subject: RE: [PATCH V5 6/8] clocksource: hyper-v: Mark hyperv tsc page unencrypted in sev-snp enlightened guest

> From: Tianyu Lan <[email protected]>
> Sent: Thursday, August 10, 2023 9:04 AM
> [...]
> Hyper-V tsc page is shared with hypervisor and mark the page
> unencrypted in sev-snp enlightened guest when it's used.
>
> Reviewed-by: Michael Kelley <[email protected]>
> Signed-off-by: Tianyu Lan <[email protected]>

Reviewed-by: Dexuan Cui <[email protected]>

FWIW, it looks like __bss_decrypted is ignored in the case of
TDX. I'll get it to work for TDX in future.