Merge branch 'x86/urgent' into x86/boot, to merge dependent commit and upstream fixes

In particular we need this fix before applying subsequent changes:

  d54d610243a4 ("x86/boot/sev: Avoid shared GHCB page for early memory acceptance")

Signed-off-by: Ingo Molnar <mingo@kernel.org>

3 files changed, 21 insertions, 53 deletions

diff --git a/arch/x86/boot/compressed/mem.c b/arch/x86/boot/compressed/mem.c
index dbba332e4a12..f676156d9f3d 100644
--- a/arch/x86/boot/compressed/mem.c
+++ b/arch/x86/boot/compressed/mem.c
@@ -34,11 +34,14 @@ static bool early_is_tdx_guest(void)
 
 void arch_accept_memory(phys_addr_t start, phys_addr_t end)
 {
+	static bool sevsnp;
+
 	/* Platform-specific memory-acceptance call goes here */
 	if (early_is_tdx_guest()) {
 		if (!tdx_accept_memory(start, end))
 			panic("TDX: Failed to accept memory\n");
-	} else if (sev_snp_enabled()) {
+	} else if (sevsnp || (sev_get_status() & MSR_AMD64_SEV_SNP_ENABLED)) {
+		sevsnp = true;
 		snp_accept_memory(start, end);
 	} else {
 		error("Cannot accept memory: unknown platform\n");
diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index 6eadd790f4e5..478eca4f7180 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -169,10 +169,7 @@ bool sev_snp_enabled(void)
 
 static void __page_state_change(unsigned long paddr, enum psc_op op)
 {
-	u64 val;
-
-	if (!sev_snp_enabled())
-		return;
+	u64 val, msr;
 
 	/*
 	 * If private -> shared then invalidate the page before requesting the
@@ -181,6 +178,9 @@ static void __page_state_change(unsigned long paddr, enum psc_op op)
 	if (op == SNP_PAGE_STATE_SHARED)
 		pvalidate_4k_page(paddr, paddr, false);
 
+	/* Save the current GHCB MSR value */
+	msr = sev_es_rd_ghcb_msr();
+
 	/* 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();
@@ -190,6 +190,9 @@ static void __page_state_change(unsigned long paddr, enum psc_op op)
 	if ((GHCB_RESP_CODE(val) != GHCB_MSR_PSC_RESP) || GHCB_MSR_PSC_RESP_VAL(val))
 		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);
 
+	/* Restore the GHCB MSR value */
+	sev_es_wr_ghcb_msr(msr);
+
 	/*
 	 * Now that page state is changed in the RMP table, validate it so that it is
 	 * consistent with the RMP entry.
@@ -200,11 +203,17 @@ static void __page_state_change(unsigned long paddr, enum psc_op op)
 
 void snp_set_page_private(unsigned long paddr)
 {
+	if (!sev_snp_enabled())
+		return;
+
 	__page_state_change(paddr, SNP_PAGE_STATE_PRIVATE);
 }
 
 void snp_set_page_shared(unsigned long paddr)
 {
+	if (!sev_snp_enabled())
+		return;
+
 	__page_state_change(paddr, SNP_PAGE_STATE_SHARED);
 }
 
@@ -228,56 +237,10 @@ static bool early_setup_ghcb(void)
 	return true;
 }
 
-static phys_addr_t __snp_accept_memory(struct snp_psc_desc *desc,
-				       phys_addr_t pa, phys_addr_t pa_end)
-{
-	struct psc_hdr *hdr;
-	struct psc_entry *e;
-	unsigned int i;
-
-	hdr = &desc->hdr;
-	memset(hdr, 0, sizeof(*hdr));
-
-	e = desc->entries;
-
-	i = 0;
-	while (pa < pa_end && i < VMGEXIT_PSC_MAX_ENTRY) {
-		hdr->end_entry = i;
-
-		e->gfn = pa >> PAGE_SHIFT;
-		e->operation = SNP_PAGE_STATE_PRIVATE;
-		if (IS_ALIGNED(pa, PMD_SIZE) && (pa_end - pa) >= PMD_SIZE) {
-			e->pagesize = RMP_PG_SIZE_2M;
-			pa += PMD_SIZE;
-		} else {
-			e->pagesize = RMP_PG_SIZE_4K;
-			pa += PAGE_SIZE;
-		}
-
-		e++;
-		i++;
-	}
-
-	if (vmgexit_psc(boot_ghcb, desc))
-		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);
-
-	pvalidate_pages(desc);
-
-	return pa;
-}
-
 void snp_accept_memory(phys_addr_t start, phys_addr_t end)
 {
-	struct snp_psc_desc desc = {};
-	unsigned int i;
-	phys_addr_t pa;
-
-	if (!boot_ghcb && !early_setup_ghcb())
-		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);
-
-	pa = start;
-	while (pa < end)
-		pa = __snp_accept_memory(&desc, pa, end);
+	for (phys_addr_t pa = start; pa < end; pa += PAGE_SIZE)
+		__page_state_change(pa, SNP_PAGE_STATE_PRIVATE);
 }
 
 void sev_es_shutdown_ghcb(void)
diff --git a/arch/x86/boot/compressed/sev.h b/arch/x86/boot/compressed/sev.h
index fc725a981b09..4e463f33186d 100644
--- a/arch/x86/boot/compressed/sev.h
+++ b/arch/x86/boot/compressed/sev.h
@@ -12,11 +12,13 @@
 
 bool sev_snp_enabled(void);
 void snp_accept_memory(phys_addr_t start, phys_addr_t end);
+u64 sev_get_status(void);
 
 #else
 
 static inline bool sev_snp_enabled(void) { return false; }
 static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { }
+static inline u64 sev_get_status(void) { return 0; }
 
 #endif