x86/microcode/AMD: Flush patch buffer mapping after application

JIRA: https://issues.redhat.com/browse/RHEL-78135

commit c809b0d
Author: Borislav Petkov (AMD) <bp@alien8.de>
Date:   Tue Nov 19 12:21:33 2024 +0100

    x86/microcode/AMD: Flush patch buffer mapping after application

    Due to specific requirements while applying microcode patches on Zen1
    and 2, the patch buffer mapping needs to be flushed from the TLB after
    application. Do so.

    If not, unnecessary and unnatural delays happen in the boot process.

    Reported-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
    Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
    Tested-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
    Cc: <stable@kernel.org> # f1d84b5 ("x86/mm: Carve out INVLPG inline asm for use by others")
    Link: https://lore.kernel.org/r/ZyulbYuvrkshfsd2@antipodes

Signed-off-by: Luiz Capitulino <luizcap@redhat.com>

Author: luiz-cap

arch/x86/kernel/cpu/microcode/amd.c

@@ -34,6 +34,7 @@
 #include <asm/setup.h>
 #include <asm/cpu.h>
 #include <asm/msr.h>
+#include <asm/tlb.h>
 
 #include "internal.h"
 
@@ -483,11 +484,25 @@ static void scan_containers(u8 *ucode, size_t size, struct cont_desc *desc)
 	}
 }
 
-static int __apply_microcode_amd(struct microcode_amd *mc)
+static int __apply_microcode_amd(struct microcode_amd *mc, unsigned int psize)
 {
+	unsigned long p_addr = (unsigned long)&mc->hdr.data_code;
 	u32 rev, dummy;
 
-	native_wrmsrl(MSR_AMD64_PATCH_LOADER, (u64)(long)&mc->hdr.data_code);
+	native_wrmsrl(MSR_AMD64_PATCH_LOADER, p_addr);
+
+	if (x86_family(bsp_cpuid_1_eax) == 0x17) {
+		unsigned long p_addr_end = p_addr + psize - 1;
+
+		invlpg(p_addr);
+
+		/*
+		 * Flush next page too if patch image is crossing a page
+		 * boundary.
+		 */
+		if (p_addr >> PAGE_SHIFT != p_addr_end >> PAGE_SHIFT)
+			invlpg(p_addr_end);
+	}
 
 	/* verify patch application was successful */
 	native_rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy);
@@ -529,7 +544,7 @@ static bool early_apply_microcode(u32 old_rev, void *ucode, size_t size)
 	if (old_rev > mc->hdr.patch_id)
 		return ret;
 
-	return !__apply_microcode_amd(mc);
+	return !__apply_microcode_amd(mc, desc.psize);
 }
 
 static bool get_builtin_microcode(struct cpio_data *cp)
@@ -745,7 +760,7 @@ void reload_ucode_amd(unsigned int cpu)
 	rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy);
 
 	if (rev < mc->hdr.patch_id) {
-		if (!__apply_microcode_amd(mc))
+		if (!__apply_microcode_amd(mc, p->size))
 			pr_info_once("reload revision: 0x%08x\n", mc->hdr.patch_id);
 	}
 }
@@ -798,7 +813,7 @@ static enum ucode_state apply_microcode_amd(int cpu)
 		goto out;
 	}
 
-	if (__apply_microcode_amd(mc_amd)) {
+	if (__apply_microcode_amd(mc_amd, p->size)) {
 		pr_err("CPU%d: update failed for patch_level=0x%08x\n",
 			cpu, mc_amd->hdr.patch_id);
 		return UCODE_ERROR;