[PATCH 6/6] LoongArch: KVM: Enable separate vmid feature

[Bibo Mao]

With CSR GTLBC shortname for Guest TLB Control Register, separate vmid
feature will be enabled if bit 14 CSR_GTLBC_USEVMID is set. Enable
this feature if cpu_has_guestid is true when LVZ is enabled and the LVZ
version is 2.

Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx>
---
 arch/loongarch/include/asm/loongarch.h | 2 ++
 arch/loongarch/kernel/cpu-probe.c      | 7 ++++++-
 arch/loongarch/kvm/main.c              | 4 +++-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/loongarch/include/asm/loongarch.h b/arch/loongarch/include/asm/loongarch.h
index 2a6bc99177d8..4c4249446a61 100644
--- a/arch/loongarch/include/asm/loongarch.h
+++ b/arch/loongarch/include/asm/loongarch.h
@@ -350,6 +350,8 @@
 #define  CSR_GTLBC_TGID_WIDTH		8
 #define  CSR_GTLBC_TGID_SHIFT_END	(CSR_GTLBC_TGID_SHIFT + CSR_GTLBC_TGID_WIDTH - 1)
 #define  CSR_GTLBC_TGID			(_ULCAST_(0xff) << CSR_GTLBC_TGID_SHIFT)
+#define  CSR_GTLBC_USEVMID_SHIFT	14
+#define  CSR_GTLBC_USEVMID		(_ULCAST_(0x1) << CSR_GTLBC_USEVMID_SHIFT)
 #define  CSR_GTLBC_TOTI_SHIFT		13
 #define  CSR_GTLBC_TOTI			(_ULCAST_(0x1) << CSR_GTLBC_TOTI_SHIFT)
 #define  CSR_GTLBC_USETGID_SHIFT	12
diff --git a/arch/loongarch/kernel/cpu-probe.c b/arch/loongarch/kernel/cpu-probe.c
index 74d31f260dfd..cbf1dafac0a0 100644
--- a/arch/loongarch/kernel/cpu-probe.c
+++ b/arch/loongarch/kernel/cpu-probe.c
@@ -135,7 +135,7 @@ static void set_isa(struct cpuinfo_loongarch *c, unsigned int isa)
 
 static void cpu_probe_common(struct cpuinfo_loongarch *c)
 {
-	unsigned int config;
+	unsigned int config, version;
 	unsigned long asid_mask;
 
 	c->options = LOONGARCH_CPU_CPUCFG | LOONGARCH_CPU_CSR | LOONGARCH_CPU_VINT;
@@ -221,6 +221,11 @@ static void cpu_probe_common(struct cpuinfo_loongarch *c)
 	if (config & CPUCFG2_LVZP) {
 		c->options |= LOONGARCH_CPU_LVZ;
 		elf_hwcap |= HWCAP_LOONGARCH_LVZ;
+
+		/* Separate VMID and VPID with LVZ version == 2 */
+		version = (config & CPUCFG2_LVZVER) >> 11;
+		if (version == 2)
+			c->options |= LOONGARCH_CPU_GUESTID;
 	}
 #ifdef CONFIG_CPU_HAS_LBT
 	if (config & CPUCFG2_X86BT) {
diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c
index 86b1af823e2b..43f5b40786f2 100644
--- a/arch/loongarch/kvm/main.c
+++ b/arch/loongarch/kvm/main.c
@@ -365,7 +365,7 @@ int kvm_arch_enable_virtualization_cpu(void)
 	write_csr_gcfg(0);
 	write_csr_gstat(0);
 	write_csr_gintc(0);
-	clear_csr_gtlbc(CSR_GTLBC_USETGID | CSR_GTLBC_TOTI);
+	clear_csr_gtlbc(CSR_GTLBC_USETGID | CSR_GTLBC_TOTI | CSR_GTLBC_USEVMID);
 
 	/*
 	 * Enable virtualization features granting guest direct control of
@@ -388,6 +388,8 @@ int kvm_arch_enable_virtualization_cpu(void)
 
 	/* Enable using TGID  */
 	set_csr_gtlbc(CSR_GTLBC_USETGID);
+	if (cpu_has_guestid)
+		set_csr_gtlbc(CSR_GTLBC_USEVMID);
 	kvm_debug("GCFG:%lx GSTAT:%lx GINTC:%lx GTLBC:%lx",
 		  read_csr_gcfg(), read_csr_gstat(), read_csr_gintc(), read_csr_gtlbc());
 
-- 
2.39.3