From 34ec27e10cc41c2ae5339a09d85edbb9533996df Mon Sep 17 00:00:00 2001
From: Haiwei Li <haiwei.li@intel.com>
Date: Fri, 21 Jun 2024 12:50:17 +0800
Subject: [PATCH] dm: pm: add s3 support for an User VM with elf/bzImage

For an elf-loaded or beImage-loaded User VM, acrn-dm is responsible for
handling s3 related matters.

After resume from S3, acrn-dm should read waking_vector and set related
registers to make guest to resume.

Tracked-On: #8536
Signed-off-by: Haiwei Li <haiwei.li@intel.com>
---
 devicemodel/core/main.c             | 27 ++++++++++++++++++++++++++-
 devicemodel/hw/platform/acpi/acpi.c | 16 ++++++++++++++++
 devicemodel/include/acpi.h          |  2 ++
 3 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/devicemodel/core/main.c b/devicemodel/core/main.c
index ff650485b8..e2d2905243 100644
--- a/devicemodel/core/main.c
+++ b/devicemodel/core/main.c
@@ -742,6 +742,7 @@ vm_system_reset(struct vmctx *ctx)
 static void
 vm_suspend_resume(struct vmctx *ctx)
 {
+	struct acrn_vcpu_regs bsp_regs;
 	/*
 	 * If we get warm reboot request, we don't want to exit the
 	 * vcpu_loop/vm_loop/mevent_loop. So we do:
@@ -764,8 +765,32 @@ vm_suspend_resume(struct vmctx *ctx)
 	vm_reset_watchdog(ctx);
 	vm_reset(ctx);
 
+	bsp_regs = ctx->bsp_regs;
+	/* for bzImage or elf */
+	if (!ovmf_loaded) {
+		uint32_t *guest_wakeup_vec32;
+		/* 64BIT_WAKE_SUPPORTED_F is not set */
+		guest_wakeup_vec32 = paddr_guest2host(ctx,
+						      get_acpi_wakingvector_offset(),
+						      get_acpi_wakingvector_length());
+		/* set the BSP waking vector */
+		bsp_regs.vcpu_regs.cs_sel = (uint16_t)((*guest_wakeup_vec32 >> 4U) & 0xFFFFU);
+		bsp_regs.vcpu_regs.cs_base = bsp_regs.vcpu_regs.cs_sel << 4U;
+		/* real mode code segment */
+		bsp_regs.vcpu_regs.cs_ar = 0x009FU;
+		bsp_regs.vcpu_regs.cs_limit = 0xFFFFU;
+		bsp_regs.vcpu_regs.rip = 0x0U;
+		/* CR0_ET | CR0_NE */
+		bsp_regs.vcpu_regs.cr0 = 0x30;
+		/* real mode gdt */
+		bsp_regs.vcpu_regs.gdt.limit = 0xFFFFU;
+		bsp_regs.vcpu_regs.gdt.base = 0UL;
+		/* real mode idt */
+		bsp_regs.vcpu_regs.idt.limit = 0xFFFFU;
+		bsp_regs.vcpu_regs.idt.base = 0UL;
+	}
 	/* set the BSP init state */
-	vm_set_vcpu_regs(ctx, &ctx->bsp_regs);
+	vm_set_vcpu_regs(ctx, &bsp_regs);
 	vm_run(ctx);
 }
 
diff --git a/devicemodel/hw/platform/acpi/acpi.c b/devicemodel/hw/platform/acpi/acpi.c
index c5f6a40af4..ea50be50ad 100644
--- a/devicemodel/hw/platform/acpi/acpi.c
+++ b/devicemodel/hw/platform/acpi/acpi.c
@@ -93,6 +93,10 @@
 #define RTCT_OFFSET		0xF00
 #define DSDT_OFFSET		0x1100
 
+/* Define the byte offset and byte length in FACS table */
+#define WAKING_VECTOR_OFFSET   12
+#define WAKING_VECTOR_LEN      4
+
 #define	ASL_TEMPLATE	"dm.XXXXXXX"
 #define ASL_SUFFIX	".aml"
 
@@ -1112,6 +1116,18 @@ get_acpi_table_length(void)
 	return ACPI_LENGTH;
 }
 
+uint32_t
+get_acpi_wakingvector_offset(void)
+{
+	return basl_acpi_base + FACS_OFFSET + WAKING_VECTOR_OFFSET;
+}
+
+uint32_t
+get_acpi_wakingvector_length(void)
+{
+	return WAKING_VECTOR_LEN;
+}
+
 int
 get_default_iasl_compiler(void)
 {
diff --git a/devicemodel/include/acpi.h b/devicemodel/include/acpi.h
index b8d088a09a..c2f68bbebe 100644
--- a/devicemodel/include/acpi.h
+++ b/devicemodel/include/acpi.h
@@ -99,6 +99,8 @@ struct acpi_madt_local_apic {
 void acpi_table_enable(int num);
 uint32_t get_acpi_base(void);
 uint32_t get_acpi_table_length(void);
+uint32_t get_acpi_wakingvector_offset(void);
+uint32_t get_acpi_wakingvector_length(void);
 
 struct vmctx;