Re: [PATCH Part1 RFC v2 11/20] x86/compressed: Add helper for validating pages in the decompression stage
From: Borislav Petkov <bp@alien8.de>
Date: 2021-05-20 17:52:41
Also in:
lkml
On Fri, Apr 30, 2021 at 07:16:07AM -0500, Brijesh Singh wrote:
quoted hunk ↗ jump to hunk
@@ -278,12 +279,28 @@ static int set_clr_page_flags(struct x86_mapping_info *info, if ((set | clr) & _PAGE_ENC) clflush_page(address); + /* + * If the encryption attribute is being cleared, then change the page state to + * shared in the RMP entry. Change of the page state must be done before the + * PTE updates. + */ + if (clr & _PAGE_ENC) + snp_set_page_shared(pte_pfn(*ptep) << PAGE_SHIFT);
From the last review: The statement above already looks at clr - just merge the two together.
quoted hunk ↗ jump to hunk
@@ -136,6 +137,55 @@ static inline bool sev_snp_enabled(void) return sev_status_val & MSR_AMD64_SEV_SNP_ENABLED ? true : false; } +static void snp_page_state_change(unsigned long paddr, int op)
From the last review: no need for too many prefixes on static functions - just call this one __change_page_state() or so, so that the below one can be called...
+{
+ u64 val;
+
+ if (!sev_snp_enabled())
+ return;
+
+ /*
+ * If the page is getting changed from private to shard then invalidate the pageshared And you can write this a lot shorter * If private -> shared, ...
+ * before requesting the state change in the RMP table. + */ + if ((op == SNP_PAGE_STATE_SHARED) && pvalidate(paddr, RMP_PG_SIZE_4K, 0)) + goto e_pvalidate; + + /* Issue VMGEXIT to change the page state in RMP table. */ + sev_es_wr_ghcb_msr(GHCB_MSR_PSC_REQ_GFN(paddr >> PAGE_SHIFT, op)); + VMGEXIT(); + + /* Read the response of the VMGEXIT. */ + val = sev_es_rd_ghcb_msr(); + if ((GHCB_RESP_CODE(val) != GHCB_MSR_PSC_RESP) || GHCB_MSR_PSC_RESP_VAL(val)) + goto e_psc;
That label is used only once - just do the termination here directly and
remove it.
Thx.
--
Regards/Gruss,
Boris.
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