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Subject[PATCH 2/3] RISC-V: KVM: Use Svinval for local TLB maintenance when available
Date
We should prefer HINVAL.GVMA and HINVAL.VVMA instruction for local TLB
maintenance when underlying host supports Svinval extension.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
arch/riscv/include/asm/insn-def.h | 20 +++++++++++
arch/riscv/kvm/tlb.c | 60 ++++++++++++++++++++++++-------
2 files changed, 68 insertions(+), 12 deletions(-)

diff --git a/arch/riscv/include/asm/insn-def.h b/arch/riscv/include/asm/insn-def.h
index 8fe9036efb68..246a627d16ee 100644
--- a/arch/riscv/include/asm/insn-def.h
+++ b/arch/riscv/include/asm/insn-def.h
@@ -110,4 +110,24 @@
__ASM_STR(.error "hlv.d requires 64-bit support")
#endif

+#define SINVAL_VMA(vaddr, asid) \
+ INSN_R(OPCODE_SYSTEM, FUNC3(0), FUNC7(11), \
+ __RD(0), RS1(vaddr), RS2(asid))
+
+#define SFENCE_W_INVAL() \
+ INSN_R(OPCODE_SYSTEM, FUNC3(0), FUNC7(12), \
+ __RD(0), __RS1(0), __RS2(0))
+
+#define SFENCE_INVAL_IR() \
+ INSN_R(OPCODE_SYSTEM, FUNC3(0), FUNC7(12), \
+ __RD(0), __RS1(0), __RS2(1))
+
+#define HINVAL_VVMA(vaddr, asid) \
+ INSN_R(OPCODE_SYSTEM, FUNC3(0), FUNC7(19), \
+ __RD(0), RS1(vaddr), RS2(asid))
+
+#define HINVAL_GVMA(gaddr, vmid) \
+ INSN_R(OPCODE_SYSTEM, FUNC3(0), FUNC7(51), \
+ __RD(0), RS1(gaddr), RS2(vmid))
+
#endif /* __ASM_INSN_DEF_H */
diff --git a/arch/riscv/kvm/tlb.c b/arch/riscv/kvm/tlb.c
index 1ce3394b3acf..309d79b3e5cd 100644
--- a/arch/riscv/kvm/tlb.c
+++ b/arch/riscv/kvm/tlb.c
@@ -12,8 +12,12 @@
#include <linux/kvm_host.h>
#include <asm/cacheflush.h>
#include <asm/csr.h>
+#include <asm/hwcap.h>
#include <asm/insn-def.h>

+#define has_svinval() \
+ static_branch_unlikely(&riscv_isa_ext_keys[RISCV_ISA_EXT_KEY_SVINVAL])
+
void kvm_riscv_local_hfence_gvma_vmid_gpa(unsigned long vmid,
gpa_t gpa, gpa_t gpsz,
unsigned long order)
@@ -25,9 +29,17 @@ void kvm_riscv_local_hfence_gvma_vmid_gpa(unsigned long vmid,
return;
}

- for (pos = gpa; pos < (gpa + gpsz); pos += BIT(order))
- asm volatile (HFENCE_GVMA(%0, %1)
- : : "r" (pos >> 2), "r" (vmid) : "memory");
+ if (has_svinval()) {
+ asm volatile (SFENCE_W_INVAL() ::: "memory");
+ for (pos = gpa; pos < (gpa + gpsz); pos += BIT(order))
+ asm volatile (HINVAL_GVMA(%0, %1)
+ : : "r" (pos >> 2), "r" (vmid) : "memory");
+ asm volatile (SFENCE_INVAL_IR() ::: "memory");
+ } else {
+ for (pos = gpa; pos < (gpa + gpsz); pos += BIT(order))
+ asm volatile (HFENCE_GVMA(%0, %1)
+ : : "r" (pos >> 2), "r" (vmid) : "memory");
+ }
}

void kvm_riscv_local_hfence_gvma_vmid_all(unsigned long vmid)
@@ -45,9 +57,17 @@ void kvm_riscv_local_hfence_gvma_gpa(gpa_t gpa, gpa_t gpsz,
return;
}

- for (pos = gpa; pos < (gpa + gpsz); pos += BIT(order))
- asm volatile(HFENCE_GVMA(%0, zero)
- : : "r" (pos >> 2) : "memory");
+ if (has_svinval()) {
+ asm volatile (SFENCE_W_INVAL() ::: "memory");
+ for (pos = gpa; pos < (gpa + gpsz); pos += BIT(order))
+ asm volatile(HINVAL_GVMA(%0, zero)
+ : : "r" (pos >> 2) : "memory");
+ asm volatile (SFENCE_INVAL_IR() ::: "memory");
+ } else {
+ for (pos = gpa; pos < (gpa + gpsz); pos += BIT(order))
+ asm volatile(HFENCE_GVMA(%0, zero)
+ : : "r" (pos >> 2) : "memory");
+ }
}

void kvm_riscv_local_hfence_gvma_all(void)
@@ -70,9 +90,17 @@ void kvm_riscv_local_hfence_vvma_asid_gva(unsigned long vmid,

hgatp = csr_swap(CSR_HGATP, vmid << HGATP_VMID_SHIFT);

- for (pos = gva; pos < (gva + gvsz); pos += BIT(order))
- asm volatile(HFENCE_VVMA(%0, %1)
- : : "r" (pos), "r" (asid) : "memory");
+ if (has_svinval()) {
+ asm volatile (SFENCE_W_INVAL() ::: "memory");
+ for (pos = gva; pos < (gva + gvsz); pos += BIT(order))
+ asm volatile(HINVAL_VVMA(%0, %1)
+ : : "r" (pos), "r" (asid) : "memory");
+ asm volatile (SFENCE_INVAL_IR() ::: "memory");
+ } else {
+ for (pos = gva; pos < (gva + gvsz); pos += BIT(order))
+ asm volatile(HFENCE_VVMA(%0, %1)
+ : : "r" (pos), "r" (asid) : "memory");
+ }

csr_write(CSR_HGATP, hgatp);
}
@@ -102,9 +130,17 @@ void kvm_riscv_local_hfence_vvma_gva(unsigned long vmid,

hgatp = csr_swap(CSR_HGATP, vmid << HGATP_VMID_SHIFT);

- for (pos = gva; pos < (gva + gvsz); pos += BIT(order))
- asm volatile(HFENCE_VVMA(%0, zero)
- : : "r" (pos) : "memory");
+ if (has_svinval()) {
+ asm volatile (SFENCE_W_INVAL() ::: "memory");
+ for (pos = gva; pos < (gva + gvsz); pos += BIT(order))
+ asm volatile(HINVAL_VVMA(%0, zero)
+ : : "r" (pos) : "memory");
+ asm volatile (SFENCE_INVAL_IR() ::: "memory");
+ } else {
+ for (pos = gva; pos < (gva + gvsz); pos += BIT(order))
+ asm volatile(HFENCE_VVMA(%0, zero)
+ : : "r" (pos) : "memory");
+ }

csr_write(CSR_HGATP, hgatp);
}
--
2.34.1
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