Merge tag 'x86_sev_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 SEV updates from Borislav Petkov:

 - A segmented Reverse Map table (RMP) is a across-nodes distributed
   table of sorts which contains per-node descriptors of each node-local
   4K page, denoting its ownership (hypervisor, guest, etc) in the realm
   of confidential computing. Add support for such a table in order to
   improve referential locality when accessing or modifying RMP table
   entries

 - Add support for reading the TSC in SNP guests by removing any
   interference or influence the hypervisor might have, with the goal of
   making a confidential guest even more independent from the hypervisor

* tag 'x86_sev_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sev: Add the Secure TSC feature for SNP guests
  x86/tsc: Init the TSC for Secure TSC guests
  x86/sev: Mark the TSC in a secure TSC guest as reliable
  x86/sev: Prevent RDTSC/RDTSCP interception for Secure TSC enabled guests
  x86/sev: Prevent GUEST_TSC_FREQ MSR interception for Secure TSC enabled guests
  x86/sev: Change TSC MSR behavior for Secure TSC enabled guests
  x86/sev: Add Secure TSC support for SNP guests
  x86/sev: Relocate SNP guest messaging routines to common code
  x86/sev: Carve out and export SNP guest messaging init routines
  virt: sev-guest: Replace GFP_KERNEL_ACCOUNT with GFP_KERNEL
  virt: sev-guest: Remove is_vmpck_empty() helper
  x86/sev/docs: Document the SNP Reverse Map Table (RMP)
  x86/sev: Add full support for a segmented RMP table
  x86/sev: Treat the contiguous RMP table as a single RMP segment
  x86/sev: Map only the RMP table entries instead of the full RMP range
  x86/sev: Move the SNP probe routine out of the way
  x86/sev: Require the RMPREAD instruction after Zen4
  x86/sev: Add support for the RMPREAD instruction
  x86/sev: Prepare for using the RMPREAD instruction to access the RMP

2 files changed, 11 insertions, 2 deletions

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 79d2e17f6582..b9592c60166e 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -355,10 +355,15 @@ static void bsp_determine_snp(struct cpuinfo_x86 *c)
 		/*
 		 * RMP table entry format is not architectural and is defined by the
 		 * per-processor PPR. Restrict SNP support on the known CPU models
-		 * for which the RMP table entry format is currently defined for.
+		 * for which the RMP table entry format is currently defined or for
+		 * processors which support the architecturally defined RMPREAD
+		 * instruction.
 		 */
 		if (!cpu_has(c, X86_FEATURE_HYPERVISOR) &&
-		    c->x86 >= 0x19 && snp_probe_rmptable_info()) {
+		    (cpu_feature_enabled(X86_FEATURE_ZEN3) ||
+		     cpu_feature_enabled(X86_FEATURE_ZEN4) ||
+		     cpu_feature_enabled(X86_FEATURE_RMPREAD)) &&
+		    snp_probe_rmptable_info()) {
 			cc_platform_set(CC_ATTR_HOST_SEV_SNP);
 		} else {
 			setup_clear_cpu_cap(X86_FEATURE_SEV_SNP);
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 67aeaba4ba9c..0864b314c26a 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -30,6 +30,7 @@
 #include <asm/i8259.h>
 #include <asm/topology.h>
 #include <asm/uv/uv.h>
+#include <asm/sev.h>
 
 unsigned int __read_mostly cpu_khz;	/* TSC clocks / usec, not used here */
 EXPORT_SYMBOL(cpu_khz);
@@ -1515,6 +1516,9 @@ void __init tsc_early_init(void)
 	/* Don't change UV TSC multi-chassis synchronization */
 	if (is_early_uv_system())
 		return;
+
+	snp_secure_tsc_init();
+
 	if (!determine_cpu_tsc_frequencies(true))
 		return;
 	tsc_enable_sched_clock();