Re: [PATCH V8 5/9] x86/sev-es: Expose sev_es_ghcb_hv_call() to call ghcb hv call out of sev code
From: Borislav Petkov <bp@alien8.de>
Date: 2021-10-21 16:22:36
Also in:
linux-arch, lkml, netdev
On Thu, Oct 21, 2021 at 11:41:05AM -0400, Tianyu Lan wrote:
quoted hunk ↗ jump to hunk
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c index ea9abd69237e..368ed36971e3 100644 --- a/arch/x86/kernel/sev-shared.c +++ b/arch/x86/kernel/sev-shared.c@@ -124,10 +124,9 @@ static enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt return ES_VMM_ERROR; } -static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, - struct es_em_ctxt *ctxt, - u64 exit_code, u64 exit_info_1, - u64 exit_info_2) +enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, bool set_ghcb_msr, + struct es_em_ctxt *ctxt, u64 exit_code, + u64 exit_info_1, u64 exit_info_2) { /* Fill in protocol and format specifiers */ ghcb->protocol_version = GHCB_PROTOCOL_MAX;@@ -137,7 +136,15 @@ static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, ghcb_set_sw_exit_info_1(ghcb, exit_info_1); ghcb_set_sw_exit_info_2(ghcb, exit_info_2); - sev_es_wr_ghcb_msr(__pa(ghcb)); + /* + * Hyper-V unenlightened guests use a paravisor for communicating and + * GHCB pages are being allocated and set up by that paravisor. Linux + * should not change ghcb page pa in such case and so add set_ghcb_msr
"... not change the GHCB page's physical address."
Remove the "so add... " rest.
Otherwise, LGTM.
Do you want me to take it through the tip tree?
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette