From: Fangyu Yu <fangyu.yu@linux.alibaba.com>
Introduces one per-VM architecture-specific fields to support runtime
configuration of the G-stage page table format:
- kvm->arch.pgd_levels: the corresponding number of page table levels
for the selected mode.
These fields replace the previous global variables
kvm_riscv_gstage_mode and kvm_riscv_gstage_pgd_levels, enabling different
virtual machines to independently select their G-stage page table format
instead of being forced to share the maximum mode detected by the kernel
at boot time.
Signed-off-by: Fangyu Yu <fangyu.yu@linux.alibaba.com>
Reviewed-by: Andrew Jones <andrew.jones@oss.qualcomm.com>
---
arch/riscv/include/asm/kvm_gstage.h | 37 ++++++++++++----
arch/riscv/include/asm/kvm_host.h | 1 +
arch/riscv/kvm/gstage.c | 65 ++++++++++++++---------------
arch/riscv/kvm/main.c | 12 +++---
arch/riscv/kvm/mmu.c | 20 +++++----
arch/riscv/kvm/vm.c | 2 +-
arch/riscv/kvm/vmid.c | 3 +-
7 files changed, 83 insertions(+), 57 deletions(-)
diff --git a/arch/riscv/include/asm/kvm_gstage.h b/arch/riscv/include/asm/kvm_gstage.h
index 595e2183173e..5aa58d1f692a 100644
--- a/arch/riscv/include/asm/kvm_gstage.h
+++ b/arch/riscv/include/asm/kvm_gstage.h
@@ -29,16 +29,22 @@ struct kvm_gstage_mapping {
#define kvm_riscv_gstage_index_bits 10
#endif
-extern unsigned long kvm_riscv_gstage_mode;
-extern unsigned long kvm_riscv_gstage_pgd_levels;
+extern unsigned long kvm_riscv_gstage_max_pgd_levels;
#define kvm_riscv_gstage_pgd_xbits 2
#define kvm_riscv_gstage_pgd_size (1UL << (HGATP_PAGE_SHIFT + kvm_riscv_gstage_pgd_xbits))
-#define kvm_riscv_gstage_gpa_bits (HGATP_PAGE_SHIFT + \
- (kvm_riscv_gstage_pgd_levels * \
- kvm_riscv_gstage_index_bits) + \
- kvm_riscv_gstage_pgd_xbits)
-#define kvm_riscv_gstage_gpa_size ((gpa_t)(1ULL << kvm_riscv_gstage_gpa_bits))
+
+static inline unsigned long kvm_riscv_gstage_gpa_bits(unsigned long pgd_levels)
+{
+ return (HGATP_PAGE_SHIFT +
+ pgd_levels * kvm_riscv_gstage_index_bits +
+ kvm_riscv_gstage_pgd_xbits);
+}
+
+static inline gpa_t kvm_riscv_gstage_gpa_size(unsigned long pgd_levels)
+{
+ return BIT_ULL(kvm_riscv_gstage_gpa_bits(pgd_levels));
+}
bool kvm_riscv_gstage_get_leaf(struct kvm_gstage *gstage, gpa_t addr,
pte_t **ptepp, u32 *ptep_level);
@@ -69,4 +75,21 @@ void kvm_riscv_gstage_wp_range(struct kvm_gstage *gstage, gpa_t start, gpa_t end
void kvm_riscv_gstage_mode_detect(void);
+static inline unsigned long kvm_riscv_gstage_mode(unsigned long pgd_levels)
+{
+ switch (pgd_levels) {
+ case 2:
+ return HGATP_MODE_SV32X4;
+ case 3:
+ return HGATP_MODE_SV39X4;
+ case 4:
+ return HGATP_MODE_SV48X4;
+ case 5:
+ return HGATP_MODE_SV57X4;
+ default:
+ WARN_ON_ONCE(1);
+ return HGATP_MODE_OFF;
+ }
+}
+
#endif
diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index 24585304c02b..478f699e9dec 100644
--- a/arch/riscv/include/asm/kvm_host.h
+++ b/arch/riscv/include/asm/kvm_host.h
@@ -94,6 +94,7 @@ struct kvm_arch {
/* G-stage page table */
pgd_t *pgd;
phys_addr_t pgd_phys;
+ unsigned long pgd_levels;
/* Guest Timer */
struct kvm_guest_timer timer;
diff --git a/arch/riscv/kvm/gstage.c b/arch/riscv/kvm/gstage.c
index b67d60d722c2..4beb9322fe76 100644
--- a/arch/riscv/kvm/gstage.c
+++ b/arch/riscv/kvm/gstage.c
@@ -12,22 +12,21 @@
#include <asm/kvm_gstage.h>
#ifdef CONFIG_64BIT
-unsigned long kvm_riscv_gstage_mode __ro_after_init = HGATP_MODE_SV39X4;
-unsigned long kvm_riscv_gstage_pgd_levels __ro_after_init = 3;
+unsigned long kvm_riscv_gstage_max_pgd_levels __ro_after_init = 3;
#else
-unsigned long kvm_riscv_gstage_mode __ro_after_init = HGATP_MODE_SV32X4;
-unsigned long kvm_riscv_gstage_pgd_levels __ro_after_init = 2;
+unsigned long kvm_riscv_gstage_max_pgd_levels __ro_after_init = 2;
#endif
#define gstage_pte_leaf(__ptep) \
(pte_val(*(__ptep)) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC))
-static inline unsigned long gstage_pte_index(gpa_t addr, u32 level)
+static inline unsigned long gstage_pte_index(struct kvm_gstage *gstage,
+ gpa_t addr, u32 level)
{
unsigned long mask;
unsigned long shift = HGATP_PAGE_SHIFT + (kvm_riscv_gstage_index_bits * level);
- if (level == (kvm_riscv_gstage_pgd_levels - 1))
+ if (level == gstage->kvm->arch.pgd_levels - 1)
mask = (PTRS_PER_PTE * (1UL << kvm_riscv_gstage_pgd_xbits)) - 1;
else
mask = PTRS_PER_PTE - 1;
@@ -40,12 +39,13 @@ static inline unsigned long gstage_pte_page_vaddr(pte_t pte)
return (unsigned long)pfn_to_virt(__page_val_to_pfn(pte_val(pte)));
}
-static int gstage_page_size_to_level(unsigned long page_size, u32 *out_level)
+static int gstage_page_size_to_level(struct kvm_gstage *gstage, unsigned long page_size,
+ u32 *out_level)
{
u32 i;
unsigned long psz = 1UL << 12;
- for (i = 0; i < kvm_riscv_gstage_pgd_levels; i++) {
+ for (i = 0; i < gstage->kvm->arch.pgd_levels; i++) {
if (page_size == (psz << (i * kvm_riscv_gstage_index_bits))) {
*out_level = i;
return 0;
@@ -55,21 +55,23 @@ static int gstage_page_size_to_level(unsigned long page_size, u32 *out_level)
return -EINVAL;
}
-static int gstage_level_to_page_order(u32 level, unsigned long *out_pgorder)
+static int gstage_level_to_page_order(struct kvm_gstage *gstage, u32 level,
+ unsigned long *out_pgorder)
{
- if (kvm_riscv_gstage_pgd_levels < level)
+ if (gstage->kvm->arch.pgd_levels < level)
return -EINVAL;
*out_pgorder = 12 + (level * kvm_riscv_gstage_index_bits);
return 0;
}
-static int gstage_level_to_page_size(u32 level, unsigned long *out_pgsize)
+static int gstage_level_to_page_size(struct kvm_gstage *gstage, u32 level,
+ unsigned long *out_pgsize)
{
int rc;
unsigned long page_order = PAGE_SHIFT;
- rc = gstage_level_to_page_order(level, &page_order);
+ rc = gstage_level_to_page_order(gstage, level, &page_order);
if (rc)
return rc;
@@ -81,11 +83,11 @@ bool kvm_riscv_gstage_get_leaf(struct kvm_gstage *gstage, gpa_t addr,
pte_t **ptepp, u32 *ptep_level)
{
pte_t *ptep;
- u32 current_level = kvm_riscv_gstage_pgd_levels - 1;
+ u32 current_level = gstage->kvm->arch.pgd_levels - 1;
*ptep_level = current_level;
ptep = (pte_t *)gstage->pgd;
- ptep = &ptep[gstage_pte_index(addr, current_level)];
+ ptep = &ptep[gstage_pte_index(gstage, addr, current_level)];
while (ptep && pte_val(ptep_get(ptep))) {
if (gstage_pte_leaf(ptep)) {
*ptep_level = current_level;
@@ -97,7 +99,7 @@ bool kvm_riscv_gstage_get_leaf(struct kvm_gstage *gstage, gpa_t addr,
current_level--;
*ptep_level = current_level;
ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep));
- ptep = &ptep[gstage_pte_index(addr, current_level)];
+ ptep = &ptep[gstage_pte_index(gstage, addr, current_level)];
} else {
ptep = NULL;
}
@@ -110,7 +112,7 @@ static void gstage_tlb_flush(struct kvm_gstage *gstage, u32 level, gpa_t addr)
{
unsigned long order = PAGE_SHIFT;
- if (gstage_level_to_page_order(level, &order))
+ if (gstage_level_to_page_order(gstage, level, &order))
return;
addr &= ~(BIT(order) - 1);
@@ -125,9 +127,9 @@ int kvm_riscv_gstage_set_pte(struct kvm_gstage *gstage,
struct kvm_mmu_memory_cache *pcache,
const struct kvm_gstage_mapping *map)
{
- u32 current_level = kvm_riscv_gstage_pgd_levels - 1;
+ u32 current_level = gstage->kvm->arch.pgd_levels - 1;
pte_t *next_ptep = (pte_t *)gstage->pgd;
- pte_t *ptep = &next_ptep[gstage_pte_index(map->addr, current_level)];
+ pte_t *ptep = &next_ptep[gstage_pte_index(gstage, map->addr, current_level)];
if (current_level < map->level)
return -EINVAL;
@@ -151,7 +153,7 @@ int kvm_riscv_gstage_set_pte(struct kvm_gstage *gstage,
}
current_level--;
- ptep = &next_ptep[gstage_pte_index(map->addr, current_level)];
+ ptep = &next_ptep[gstage_pte_index(gstage, map->addr, current_level)];
}
if (pte_val(*ptep) != pte_val(map->pte)) {
@@ -175,7 +177,7 @@ int kvm_riscv_gstage_map_page(struct kvm_gstage *gstage,
out_map->addr = gpa;
out_map->level = 0;
- ret = gstage_page_size_to_level(page_size, &out_map->level);
+ ret = gstage_page_size_to_level(gstage, page_size, &out_map->level);
if (ret)
return ret;
@@ -217,7 +219,7 @@ void kvm_riscv_gstage_op_pte(struct kvm_gstage *gstage, gpa_t addr,
u32 next_ptep_level;
unsigned long next_page_size, page_size;
- ret = gstage_level_to_page_size(ptep_level, &page_size);
+ ret = gstage_level_to_page_size(gstage, ptep_level, &page_size);
if (ret)
return;
@@ -229,7 +231,7 @@ void kvm_riscv_gstage_op_pte(struct kvm_gstage *gstage, gpa_t addr,
if (ptep_level && !gstage_pte_leaf(ptep)) {
next_ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep));
next_ptep_level = ptep_level - 1;
- ret = gstage_level_to_page_size(next_ptep_level, &next_page_size);
+ ret = gstage_level_to_page_size(gstage, next_ptep_level, &next_page_size);
if (ret)
return;
@@ -263,7 +265,7 @@ void kvm_riscv_gstage_unmap_range(struct kvm_gstage *gstage,
while (addr < end) {
found_leaf = kvm_riscv_gstage_get_leaf(gstage, addr, &ptep, &ptep_level);
- ret = gstage_level_to_page_size(ptep_level, &page_size);
+ ret = gstage_level_to_page_size(gstage, ptep_level, &page_size);
if (ret)
break;
@@ -297,7 +299,7 @@ void kvm_riscv_gstage_wp_range(struct kvm_gstage *gstage, gpa_t start, gpa_t end
while (addr < end) {
found_leaf = kvm_riscv_gstage_get_leaf(gstage, addr, &ptep, &ptep_level);
- ret = gstage_level_to_page_size(ptep_level, &page_size);
+ ret = gstage_level_to_page_size(gstage, ptep_level, &page_size);
if (ret)
break;
@@ -319,39 +321,34 @@ void __init kvm_riscv_gstage_mode_detect(void)
/* Try Sv57x4 G-stage mode */
csr_write(CSR_HGATP, HGATP_MODE_SV57X4 << HGATP_MODE_SHIFT);
if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV57X4) {
- kvm_riscv_gstage_mode = HGATP_MODE_SV57X4;
- kvm_riscv_gstage_pgd_levels = 5;
+ kvm_riscv_gstage_max_pgd_levels = 5;
goto done;
}
/* Try Sv48x4 G-stage mode */
csr_write(CSR_HGATP, HGATP_MODE_SV48X4 << HGATP_MODE_SHIFT);
if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV48X4) {
- kvm_riscv_gstage_mode = HGATP_MODE_SV48X4;
- kvm_riscv_gstage_pgd_levels = 4;
+ kvm_riscv_gstage_max_pgd_levels = 4;
goto done;
}
/* Try Sv39x4 G-stage mode */
csr_write(CSR_HGATP, HGATP_MODE_SV39X4 << HGATP_MODE_SHIFT);
if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV39X4) {
- kvm_riscv_gstage_mode = HGATP_MODE_SV39X4;
- kvm_riscv_gstage_pgd_levels = 3;
+ kvm_riscv_gstage_max_pgd_levels = 3;
goto done;
}
#else /* CONFIG_32BIT */
/* Try Sv32x4 G-stage mode */
csr_write(CSR_HGATP, HGATP_MODE_SV32X4 << HGATP_MODE_SHIFT);
if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV32X4) {
- kvm_riscv_gstage_mode = HGATP_MODE_SV32X4;
- kvm_riscv_gstage_pgd_levels = 2;
+ kvm_riscv_gstage_max_pgd_levels = 2;
goto done;
}
#endif
/* KVM depends on !HGATP_MODE_OFF */
- kvm_riscv_gstage_mode = HGATP_MODE_OFF;
- kvm_riscv_gstage_pgd_levels = 0;
+ kvm_riscv_gstage_max_pgd_levels = 0;
done:
csr_write(CSR_HGATP, 0);
diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c
index 0f3fe3986fc0..90ee0a032b9a 100644
--- a/arch/riscv/kvm/main.c
+++ b/arch/riscv/kvm/main.c
@@ -105,17 +105,17 @@ static int __init riscv_kvm_init(void)
return rc;
kvm_riscv_gstage_mode_detect();
- switch (kvm_riscv_gstage_mode) {
- case HGATP_MODE_SV32X4:
+ switch (kvm_riscv_gstage_max_pgd_levels) {
+ case 2:
str = "Sv32x4";
break;
- case HGATP_MODE_SV39X4:
+ case 3:
str = "Sv39x4";
break;
- case HGATP_MODE_SV48X4:
+ case 4:
str = "Sv48x4";
break;
- case HGATP_MODE_SV57X4:
+ case 5:
str = "Sv57x4";
break;
default:
@@ -164,7 +164,7 @@ static int __init riscv_kvm_init(void)
(rc) ? slist : "no features");
}
- kvm_info("using %s G-stage page table format\n", str);
+ kvm_info("highest G-stage page table mode is %s\n", str);
kvm_info("VMID %ld bits available\n", kvm_riscv_gstage_vmid_bits());
diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
index 088d33ba90ed..fbcdd75cb9af 100644
--- a/arch/riscv/kvm/mmu.c
+++ b/arch/riscv/kvm/mmu.c
@@ -67,7 +67,7 @@ int kvm_riscv_mmu_ioremap(struct kvm *kvm, gpa_t gpa, phys_addr_t hpa,
if (!writable)
map.pte = pte_wrprotect(map.pte);
- ret = kvm_mmu_topup_memory_cache(&pcache, kvm_riscv_gstage_pgd_levels);
+ ret = kvm_mmu_topup_memory_cache(&pcache, kvm->arch.pgd_levels);
if (ret)
goto out;
@@ -186,7 +186,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
* space addressable by the KVM guest GPA space.
*/
if ((new->base_gfn + new->npages) >=
- (kvm_riscv_gstage_gpa_size >> PAGE_SHIFT))
+ kvm_riscv_gstage_gpa_size(kvm->arch.pgd_levels) >> PAGE_SHIFT)
return -EFAULT;
hva = new->userspace_addr;
@@ -472,7 +472,7 @@ int kvm_riscv_mmu_map(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
memset(out_map, 0, sizeof(*out_map));
/* We need minimum second+third level pages */
- ret = kvm_mmu_topup_memory_cache(pcache, kvm_riscv_gstage_pgd_levels);
+ ret = kvm_mmu_topup_memory_cache(pcache, kvm->arch.pgd_levels);
if (ret) {
kvm_err("Failed to topup G-stage cache\n");
return ret;
@@ -575,6 +575,7 @@ int kvm_riscv_mmu_alloc_pgd(struct kvm *kvm)
return -ENOMEM;
kvm->arch.pgd = page_to_virt(pgd_page);
kvm->arch.pgd_phys = page_to_phys(pgd_page);
+ kvm->arch.pgd_levels = kvm_riscv_gstage_max_pgd_levels;
return 0;
}
@@ -590,10 +591,12 @@ void kvm_riscv_mmu_free_pgd(struct kvm *kvm)
gstage.flags = 0;
gstage.vmid = READ_ONCE(kvm->arch.vmid.vmid);
gstage.pgd = kvm->arch.pgd;
- kvm_riscv_gstage_unmap_range(&gstage, 0UL, kvm_riscv_gstage_gpa_size, false);
+ kvm_riscv_gstage_unmap_range(&gstage, 0UL,
+ kvm_riscv_gstage_gpa_size(kvm->arch.pgd_levels), false);
pgd = READ_ONCE(kvm->arch.pgd);
kvm->arch.pgd = NULL;
kvm->arch.pgd_phys = 0;
+ kvm->arch.pgd_levels = 0;
}
spin_unlock(&kvm->mmu_lock);
@@ -603,11 +606,12 @@ void kvm_riscv_mmu_free_pgd(struct kvm *kvm)
void kvm_riscv_mmu_update_hgatp(struct kvm_vcpu *vcpu)
{
- unsigned long hgatp = kvm_riscv_gstage_mode << HGATP_MODE_SHIFT;
- struct kvm_arch *k = &vcpu->kvm->arch;
+ struct kvm_arch *ka = &vcpu->kvm->arch;
+ unsigned long hgatp = kvm_riscv_gstage_mode(ka->pgd_levels)
+ << HGATP_MODE_SHIFT;
- hgatp |= (READ_ONCE(k->vmid.vmid) << HGATP_VMID_SHIFT) & HGATP_VMID;
- hgatp |= (k->pgd_phys >> PAGE_SHIFT) & HGATP_PPN;
+ hgatp |= (READ_ONCE(ka->vmid.vmid) << HGATP_VMID_SHIFT) & HGATP_VMID;
+ hgatp |= (ka->pgd_phys >> PAGE_SHIFT) & HGATP_PPN;
ncsr_write(CSR_HGATP, hgatp);
diff --git a/arch/riscv/kvm/vm.c b/arch/riscv/kvm/vm.c
index 13c63ae1a78b..4d82a886102c 100644
--- a/arch/riscv/kvm/vm.c
+++ b/arch/riscv/kvm/vm.c
@@ -199,7 +199,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
r = KVM_USER_MEM_SLOTS;
break;
case KVM_CAP_VM_GPA_BITS:
- r = kvm_riscv_gstage_gpa_bits;
+ r = kvm_riscv_gstage_gpa_bits(kvm->arch.pgd_levels);
break;
default:
r = 0;
diff --git a/arch/riscv/kvm/vmid.c b/arch/riscv/kvm/vmid.c
index cf34d448289d..c15bdb1dd8be 100644
--- a/arch/riscv/kvm/vmid.c
+++ b/arch/riscv/kvm/vmid.c
@@ -26,7 +26,8 @@ static DEFINE_SPINLOCK(vmid_lock);
void __init kvm_riscv_gstage_vmid_detect(void)
{
/* Figure-out number of VMID bits in HW */
- csr_write(CSR_HGATP, (kvm_riscv_gstage_mode << HGATP_MODE_SHIFT) | HGATP_VMID);
+ csr_write(CSR_HGATP, (kvm_riscv_gstage_mode(kvm_riscv_gstage_max_pgd_levels) <<
+ HGATP_MODE_SHIFT) | HGATP_VMID);
vmid_bits = csr_read(CSR_HGATP);
vmid_bits = (vmid_bits & HGATP_VMID) >> HGATP_VMID_SHIFT;
vmid_bits = fls_long(vmid_bits);
--
2.50.1On Mon, Mar 30, 2026 at 5:56 PM <fangyu.yu@linux.alibaba.com> wrote:
>
> From: Fangyu Yu <fangyu.yu@linux.alibaba.com>
>
> Introduces one per-VM architecture-specific fields to support runtime
> configuration of the G-stage page table format:
>
> - kvm->arch.pgd_levels: the corresponding number of page table levels
> for the selected mode.
>
> These fields replace the previous global variables
> kvm_riscv_gstage_mode and kvm_riscv_gstage_pgd_levels, enabling different
> virtual machines to independently select their G-stage page table format
> instead of being forced to share the maximum mode detected by the kernel
> at boot time.
>
> Signed-off-by: Fangyu Yu <fangyu.yu@linux.alibaba.com>
> Reviewed-by: Andrew Jones <andrew.jones@oss.qualcomm.com>
LGTM.
Reviewed-by: Anup Patel <anup@brainfault.org>
Thanks,
Anup
> ---
> arch/riscv/include/asm/kvm_gstage.h | 37 ++++++++++++----
> arch/riscv/include/asm/kvm_host.h | 1 +
> arch/riscv/kvm/gstage.c | 65 ++++++++++++++---------------
> arch/riscv/kvm/main.c | 12 +++---
> arch/riscv/kvm/mmu.c | 20 +++++----
> arch/riscv/kvm/vm.c | 2 +-
> arch/riscv/kvm/vmid.c | 3 +-
> 7 files changed, 83 insertions(+), 57 deletions(-)
>
> diff --git a/arch/riscv/include/asm/kvm_gstage.h b/arch/riscv/include/asm/kvm_gstage.h
> index 595e2183173e..5aa58d1f692a 100644
> --- a/arch/riscv/include/asm/kvm_gstage.h
> +++ b/arch/riscv/include/asm/kvm_gstage.h
> @@ -29,16 +29,22 @@ struct kvm_gstage_mapping {
> #define kvm_riscv_gstage_index_bits 10
> #endif
>
> -extern unsigned long kvm_riscv_gstage_mode;
> -extern unsigned long kvm_riscv_gstage_pgd_levels;
> +extern unsigned long kvm_riscv_gstage_max_pgd_levels;
>
> #define kvm_riscv_gstage_pgd_xbits 2
> #define kvm_riscv_gstage_pgd_size (1UL << (HGATP_PAGE_SHIFT + kvm_riscv_gstage_pgd_xbits))
> -#define kvm_riscv_gstage_gpa_bits (HGATP_PAGE_SHIFT + \
> - (kvm_riscv_gstage_pgd_levels * \
> - kvm_riscv_gstage_index_bits) + \
> - kvm_riscv_gstage_pgd_xbits)
> -#define kvm_riscv_gstage_gpa_size ((gpa_t)(1ULL << kvm_riscv_gstage_gpa_bits))
> +
> +static inline unsigned long kvm_riscv_gstage_gpa_bits(unsigned long pgd_levels)
> +{
> + return (HGATP_PAGE_SHIFT +
> + pgd_levels * kvm_riscv_gstage_index_bits +
> + kvm_riscv_gstage_pgd_xbits);
> +}
> +
> +static inline gpa_t kvm_riscv_gstage_gpa_size(unsigned long pgd_levels)
> +{
> + return BIT_ULL(kvm_riscv_gstage_gpa_bits(pgd_levels));
> +}
>
> bool kvm_riscv_gstage_get_leaf(struct kvm_gstage *gstage, gpa_t addr,
> pte_t **ptepp, u32 *ptep_level);
> @@ -69,4 +75,21 @@ void kvm_riscv_gstage_wp_range(struct kvm_gstage *gstage, gpa_t start, gpa_t end
>
> void kvm_riscv_gstage_mode_detect(void);
>
> +static inline unsigned long kvm_riscv_gstage_mode(unsigned long pgd_levels)
> +{
> + switch (pgd_levels) {
> + case 2:
> + return HGATP_MODE_SV32X4;
> + case 3:
> + return HGATP_MODE_SV39X4;
> + case 4:
> + return HGATP_MODE_SV48X4;
> + case 5:
> + return HGATP_MODE_SV57X4;
> + default:
> + WARN_ON_ONCE(1);
> + return HGATP_MODE_OFF;
> + }
> +}
> +
> #endif
> diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
> index 24585304c02b..478f699e9dec 100644
> --- a/arch/riscv/include/asm/kvm_host.h
> +++ b/arch/riscv/include/asm/kvm_host.h
> @@ -94,6 +94,7 @@ struct kvm_arch {
> /* G-stage page table */
> pgd_t *pgd;
> phys_addr_t pgd_phys;
> + unsigned long pgd_levels;
>
> /* Guest Timer */
> struct kvm_guest_timer timer;
> diff --git a/arch/riscv/kvm/gstage.c b/arch/riscv/kvm/gstage.c
> index b67d60d722c2..4beb9322fe76 100644
> --- a/arch/riscv/kvm/gstage.c
> +++ b/arch/riscv/kvm/gstage.c
> @@ -12,22 +12,21 @@
> #include <asm/kvm_gstage.h>
>
> #ifdef CONFIG_64BIT
> -unsigned long kvm_riscv_gstage_mode __ro_after_init = HGATP_MODE_SV39X4;
> -unsigned long kvm_riscv_gstage_pgd_levels __ro_after_init = 3;
> +unsigned long kvm_riscv_gstage_max_pgd_levels __ro_after_init = 3;
> #else
> -unsigned long kvm_riscv_gstage_mode __ro_after_init = HGATP_MODE_SV32X4;
> -unsigned long kvm_riscv_gstage_pgd_levels __ro_after_init = 2;
> +unsigned long kvm_riscv_gstage_max_pgd_levels __ro_after_init = 2;
> #endif
>
> #define gstage_pte_leaf(__ptep) \
> (pte_val(*(__ptep)) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC))
>
> -static inline unsigned long gstage_pte_index(gpa_t addr, u32 level)
> +static inline unsigned long gstage_pte_index(struct kvm_gstage *gstage,
> + gpa_t addr, u32 level)
> {
> unsigned long mask;
> unsigned long shift = HGATP_PAGE_SHIFT + (kvm_riscv_gstage_index_bits * level);
>
> - if (level == (kvm_riscv_gstage_pgd_levels - 1))
> + if (level == gstage->kvm->arch.pgd_levels - 1)
> mask = (PTRS_PER_PTE * (1UL << kvm_riscv_gstage_pgd_xbits)) - 1;
> else
> mask = PTRS_PER_PTE - 1;
> @@ -40,12 +39,13 @@ static inline unsigned long gstage_pte_page_vaddr(pte_t pte)
> return (unsigned long)pfn_to_virt(__page_val_to_pfn(pte_val(pte)));
> }
>
> -static int gstage_page_size_to_level(unsigned long page_size, u32 *out_level)
> +static int gstage_page_size_to_level(struct kvm_gstage *gstage, unsigned long page_size,
> + u32 *out_level)
> {
> u32 i;
> unsigned long psz = 1UL << 12;
>
> - for (i = 0; i < kvm_riscv_gstage_pgd_levels; i++) {
> + for (i = 0; i < gstage->kvm->arch.pgd_levels; i++) {
> if (page_size == (psz << (i * kvm_riscv_gstage_index_bits))) {
> *out_level = i;
> return 0;
> @@ -55,21 +55,23 @@ static int gstage_page_size_to_level(unsigned long page_size, u32 *out_level)
> return -EINVAL;
> }
>
> -static int gstage_level_to_page_order(u32 level, unsigned long *out_pgorder)
> +static int gstage_level_to_page_order(struct kvm_gstage *gstage, u32 level,
> + unsigned long *out_pgorder)
> {
> - if (kvm_riscv_gstage_pgd_levels < level)
> + if (gstage->kvm->arch.pgd_levels < level)
> return -EINVAL;
>
> *out_pgorder = 12 + (level * kvm_riscv_gstage_index_bits);
> return 0;
> }
>
> -static int gstage_level_to_page_size(u32 level, unsigned long *out_pgsize)
> +static int gstage_level_to_page_size(struct kvm_gstage *gstage, u32 level,
> + unsigned long *out_pgsize)
> {
> int rc;
> unsigned long page_order = PAGE_SHIFT;
>
> - rc = gstage_level_to_page_order(level, &page_order);
> + rc = gstage_level_to_page_order(gstage, level, &page_order);
> if (rc)
> return rc;
>
> @@ -81,11 +83,11 @@ bool kvm_riscv_gstage_get_leaf(struct kvm_gstage *gstage, gpa_t addr,
> pte_t **ptepp, u32 *ptep_level)
> {
> pte_t *ptep;
> - u32 current_level = kvm_riscv_gstage_pgd_levels - 1;
> + u32 current_level = gstage->kvm->arch.pgd_levels - 1;
>
> *ptep_level = current_level;
> ptep = (pte_t *)gstage->pgd;
> - ptep = &ptep[gstage_pte_index(addr, current_level)];
> + ptep = &ptep[gstage_pte_index(gstage, addr, current_level)];
> while (ptep && pte_val(ptep_get(ptep))) {
> if (gstage_pte_leaf(ptep)) {
> *ptep_level = current_level;
> @@ -97,7 +99,7 @@ bool kvm_riscv_gstage_get_leaf(struct kvm_gstage *gstage, gpa_t addr,
> current_level--;
> *ptep_level = current_level;
> ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep));
> - ptep = &ptep[gstage_pte_index(addr, current_level)];
> + ptep = &ptep[gstage_pte_index(gstage, addr, current_level)];
> } else {
> ptep = NULL;
> }
> @@ -110,7 +112,7 @@ static void gstage_tlb_flush(struct kvm_gstage *gstage, u32 level, gpa_t addr)
> {
> unsigned long order = PAGE_SHIFT;
>
> - if (gstage_level_to_page_order(level, &order))
> + if (gstage_level_to_page_order(gstage, level, &order))
> return;
> addr &= ~(BIT(order) - 1);
>
> @@ -125,9 +127,9 @@ int kvm_riscv_gstage_set_pte(struct kvm_gstage *gstage,
> struct kvm_mmu_memory_cache *pcache,
> const struct kvm_gstage_mapping *map)
> {
> - u32 current_level = kvm_riscv_gstage_pgd_levels - 1;
> + u32 current_level = gstage->kvm->arch.pgd_levels - 1;
> pte_t *next_ptep = (pte_t *)gstage->pgd;
> - pte_t *ptep = &next_ptep[gstage_pte_index(map->addr, current_level)];
> + pte_t *ptep = &next_ptep[gstage_pte_index(gstage, map->addr, current_level)];
>
> if (current_level < map->level)
> return -EINVAL;
> @@ -151,7 +153,7 @@ int kvm_riscv_gstage_set_pte(struct kvm_gstage *gstage,
> }
>
> current_level--;
> - ptep = &next_ptep[gstage_pte_index(map->addr, current_level)];
> + ptep = &next_ptep[gstage_pte_index(gstage, map->addr, current_level)];
> }
>
> if (pte_val(*ptep) != pte_val(map->pte)) {
> @@ -175,7 +177,7 @@ int kvm_riscv_gstage_map_page(struct kvm_gstage *gstage,
> out_map->addr = gpa;
> out_map->level = 0;
>
> - ret = gstage_page_size_to_level(page_size, &out_map->level);
> + ret = gstage_page_size_to_level(gstage, page_size, &out_map->level);
> if (ret)
> return ret;
>
> @@ -217,7 +219,7 @@ void kvm_riscv_gstage_op_pte(struct kvm_gstage *gstage, gpa_t addr,
> u32 next_ptep_level;
> unsigned long next_page_size, page_size;
>
> - ret = gstage_level_to_page_size(ptep_level, &page_size);
> + ret = gstage_level_to_page_size(gstage, ptep_level, &page_size);
> if (ret)
> return;
>
> @@ -229,7 +231,7 @@ void kvm_riscv_gstage_op_pte(struct kvm_gstage *gstage, gpa_t addr,
> if (ptep_level && !gstage_pte_leaf(ptep)) {
> next_ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep));
> next_ptep_level = ptep_level - 1;
> - ret = gstage_level_to_page_size(next_ptep_level, &next_page_size);
> + ret = gstage_level_to_page_size(gstage, next_ptep_level, &next_page_size);
> if (ret)
> return;
>
> @@ -263,7 +265,7 @@ void kvm_riscv_gstage_unmap_range(struct kvm_gstage *gstage,
>
> while (addr < end) {
> found_leaf = kvm_riscv_gstage_get_leaf(gstage, addr, &ptep, &ptep_level);
> - ret = gstage_level_to_page_size(ptep_level, &page_size);
> + ret = gstage_level_to_page_size(gstage, ptep_level, &page_size);
> if (ret)
> break;
>
> @@ -297,7 +299,7 @@ void kvm_riscv_gstage_wp_range(struct kvm_gstage *gstage, gpa_t start, gpa_t end
>
> while (addr < end) {
> found_leaf = kvm_riscv_gstage_get_leaf(gstage, addr, &ptep, &ptep_level);
> - ret = gstage_level_to_page_size(ptep_level, &page_size);
> + ret = gstage_level_to_page_size(gstage, ptep_level, &page_size);
> if (ret)
> break;
>
> @@ -319,39 +321,34 @@ void __init kvm_riscv_gstage_mode_detect(void)
> /* Try Sv57x4 G-stage mode */
> csr_write(CSR_HGATP, HGATP_MODE_SV57X4 << HGATP_MODE_SHIFT);
> if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV57X4) {
> - kvm_riscv_gstage_mode = HGATP_MODE_SV57X4;
> - kvm_riscv_gstage_pgd_levels = 5;
> + kvm_riscv_gstage_max_pgd_levels = 5;
> goto done;
> }
>
> /* Try Sv48x4 G-stage mode */
> csr_write(CSR_HGATP, HGATP_MODE_SV48X4 << HGATP_MODE_SHIFT);
> if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV48X4) {
> - kvm_riscv_gstage_mode = HGATP_MODE_SV48X4;
> - kvm_riscv_gstage_pgd_levels = 4;
> + kvm_riscv_gstage_max_pgd_levels = 4;
> goto done;
> }
>
> /* Try Sv39x4 G-stage mode */
> csr_write(CSR_HGATP, HGATP_MODE_SV39X4 << HGATP_MODE_SHIFT);
> if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV39X4) {
> - kvm_riscv_gstage_mode = HGATP_MODE_SV39X4;
> - kvm_riscv_gstage_pgd_levels = 3;
> + kvm_riscv_gstage_max_pgd_levels = 3;
> goto done;
> }
> #else /* CONFIG_32BIT */
> /* Try Sv32x4 G-stage mode */
> csr_write(CSR_HGATP, HGATP_MODE_SV32X4 << HGATP_MODE_SHIFT);
> if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV32X4) {
> - kvm_riscv_gstage_mode = HGATP_MODE_SV32X4;
> - kvm_riscv_gstage_pgd_levels = 2;
> + kvm_riscv_gstage_max_pgd_levels = 2;
> goto done;
> }
> #endif
>
> /* KVM depends on !HGATP_MODE_OFF */
> - kvm_riscv_gstage_mode = HGATP_MODE_OFF;
> - kvm_riscv_gstage_pgd_levels = 0;
> + kvm_riscv_gstage_max_pgd_levels = 0;
>
> done:
> csr_write(CSR_HGATP, 0);
> diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c
> index 0f3fe3986fc0..90ee0a032b9a 100644
> --- a/arch/riscv/kvm/main.c
> +++ b/arch/riscv/kvm/main.c
> @@ -105,17 +105,17 @@ static int __init riscv_kvm_init(void)
> return rc;
>
> kvm_riscv_gstage_mode_detect();
> - switch (kvm_riscv_gstage_mode) {
> - case HGATP_MODE_SV32X4:
> + switch (kvm_riscv_gstage_max_pgd_levels) {
> + case 2:
> str = "Sv32x4";
> break;
> - case HGATP_MODE_SV39X4:
> + case 3:
> str = "Sv39x4";
> break;
> - case HGATP_MODE_SV48X4:
> + case 4:
> str = "Sv48x4";
> break;
> - case HGATP_MODE_SV57X4:
> + case 5:
> str = "Sv57x4";
> break;
> default:
> @@ -164,7 +164,7 @@ static int __init riscv_kvm_init(void)
> (rc) ? slist : "no features");
> }
>
> - kvm_info("using %s G-stage page table format\n", str);
> + kvm_info("highest G-stage page table mode is %s\n", str);
>
> kvm_info("VMID %ld bits available\n", kvm_riscv_gstage_vmid_bits());
>
> diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
> index 088d33ba90ed..fbcdd75cb9af 100644
> --- a/arch/riscv/kvm/mmu.c
> +++ b/arch/riscv/kvm/mmu.c
> @@ -67,7 +67,7 @@ int kvm_riscv_mmu_ioremap(struct kvm *kvm, gpa_t gpa, phys_addr_t hpa,
> if (!writable)
> map.pte = pte_wrprotect(map.pte);
>
> - ret = kvm_mmu_topup_memory_cache(&pcache, kvm_riscv_gstage_pgd_levels);
> + ret = kvm_mmu_topup_memory_cache(&pcache, kvm->arch.pgd_levels);
> if (ret)
> goto out;
>
> @@ -186,7 +186,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
> * space addressable by the KVM guest GPA space.
> */
> if ((new->base_gfn + new->npages) >=
> - (kvm_riscv_gstage_gpa_size >> PAGE_SHIFT))
> + kvm_riscv_gstage_gpa_size(kvm->arch.pgd_levels) >> PAGE_SHIFT)
> return -EFAULT;
>
> hva = new->userspace_addr;
> @@ -472,7 +472,7 @@ int kvm_riscv_mmu_map(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
> memset(out_map, 0, sizeof(*out_map));
>
> /* We need minimum second+third level pages */
> - ret = kvm_mmu_topup_memory_cache(pcache, kvm_riscv_gstage_pgd_levels);
> + ret = kvm_mmu_topup_memory_cache(pcache, kvm->arch.pgd_levels);
> if (ret) {
> kvm_err("Failed to topup G-stage cache\n");
> return ret;
> @@ -575,6 +575,7 @@ int kvm_riscv_mmu_alloc_pgd(struct kvm *kvm)
> return -ENOMEM;
> kvm->arch.pgd = page_to_virt(pgd_page);
> kvm->arch.pgd_phys = page_to_phys(pgd_page);
> + kvm->arch.pgd_levels = kvm_riscv_gstage_max_pgd_levels;
>
> return 0;
> }
> @@ -590,10 +591,12 @@ void kvm_riscv_mmu_free_pgd(struct kvm *kvm)
> gstage.flags = 0;
> gstage.vmid = READ_ONCE(kvm->arch.vmid.vmid);
> gstage.pgd = kvm->arch.pgd;
> - kvm_riscv_gstage_unmap_range(&gstage, 0UL, kvm_riscv_gstage_gpa_size, false);
> + kvm_riscv_gstage_unmap_range(&gstage, 0UL,
> + kvm_riscv_gstage_gpa_size(kvm->arch.pgd_levels), false);
> pgd = READ_ONCE(kvm->arch.pgd);
> kvm->arch.pgd = NULL;
> kvm->arch.pgd_phys = 0;
> + kvm->arch.pgd_levels = 0;
> }
> spin_unlock(&kvm->mmu_lock);
>
> @@ -603,11 +606,12 @@ void kvm_riscv_mmu_free_pgd(struct kvm *kvm)
>
> void kvm_riscv_mmu_update_hgatp(struct kvm_vcpu *vcpu)
> {
> - unsigned long hgatp = kvm_riscv_gstage_mode << HGATP_MODE_SHIFT;
> - struct kvm_arch *k = &vcpu->kvm->arch;
> + struct kvm_arch *ka = &vcpu->kvm->arch;
> + unsigned long hgatp = kvm_riscv_gstage_mode(ka->pgd_levels)
> + << HGATP_MODE_SHIFT;
>
> - hgatp |= (READ_ONCE(k->vmid.vmid) << HGATP_VMID_SHIFT) & HGATP_VMID;
> - hgatp |= (k->pgd_phys >> PAGE_SHIFT) & HGATP_PPN;
> + hgatp |= (READ_ONCE(ka->vmid.vmid) << HGATP_VMID_SHIFT) & HGATP_VMID;
> + hgatp |= (ka->pgd_phys >> PAGE_SHIFT) & HGATP_PPN;
>
> ncsr_write(CSR_HGATP, hgatp);
>
> diff --git a/arch/riscv/kvm/vm.c b/arch/riscv/kvm/vm.c
> index 13c63ae1a78b..4d82a886102c 100644
> --- a/arch/riscv/kvm/vm.c
> +++ b/arch/riscv/kvm/vm.c
> @@ -199,7 +199,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
> r = KVM_USER_MEM_SLOTS;
> break;
> case KVM_CAP_VM_GPA_BITS:
> - r = kvm_riscv_gstage_gpa_bits;
> + r = kvm_riscv_gstage_gpa_bits(kvm->arch.pgd_levels);
> break;
> default:
> r = 0;
> diff --git a/arch/riscv/kvm/vmid.c b/arch/riscv/kvm/vmid.c
> index cf34d448289d..c15bdb1dd8be 100644
> --- a/arch/riscv/kvm/vmid.c
> +++ b/arch/riscv/kvm/vmid.c
> @@ -26,7 +26,8 @@ static DEFINE_SPINLOCK(vmid_lock);
> void __init kvm_riscv_gstage_vmid_detect(void)
> {
> /* Figure-out number of VMID bits in HW */
> - csr_write(CSR_HGATP, (kvm_riscv_gstage_mode << HGATP_MODE_SHIFT) | HGATP_VMID);
> + csr_write(CSR_HGATP, (kvm_riscv_gstage_mode(kvm_riscv_gstage_max_pgd_levels) <<
> + HGATP_MODE_SHIFT) | HGATP_VMID);
> vmid_bits = csr_read(CSR_HGATP);
> vmid_bits = (vmid_bits & HGATP_VMID) >> HGATP_VMID_SHIFT;
> vmid_bits = fls_long(vmid_bits);
> --
> 2.50.1
>
On Mon, Mar 30, 2026 at 8:26 PM <fangyu.yu@linux.alibaba.com> wrote:
>
> From: Fangyu Yu <fangyu.yu@linux.alibaba.com>
>
> Introduces one per-VM architecture-specific fields to support runtime
> configuration of the G-stage page table format:
>
> - kvm->arch.pgd_levels: the corresponding number of page table levels
> for the selected mode.
>
> These fields replace the previous global variables
> kvm_riscv_gstage_mode and kvm_riscv_gstage_pgd_levels, enabling different
> virtual machines to independently select their G-stage page table format
> instead of being forced to share the maximum mode detected by the kernel
> at boot time.
>
> Signed-off-by: Fangyu Yu <fangyu.yu@linux.alibaba.com>
> Reviewed-by: Andrew Jones <andrew.jones@oss.qualcomm.com>
> ---
> arch/riscv/include/asm/kvm_gstage.h | 37 ++++++++++++----
> arch/riscv/include/asm/kvm_host.h | 1 +
> arch/riscv/kvm/gstage.c | 65 ++++++++++++++---------------
> arch/riscv/kvm/main.c | 12 +++---
> arch/riscv/kvm/mmu.c | 20 +++++----
> arch/riscv/kvm/vm.c | 2 +-
> arch/riscv/kvm/vmid.c | 3 +-
> 7 files changed, 83 insertions(+), 57 deletions(-)
>
> diff --git a/arch/riscv/include/asm/kvm_gstage.h b/arch/riscv/include/asm/kvm_gstage.h
> index 595e2183173e..5aa58d1f692a 100644
> --- a/arch/riscv/include/asm/kvm_gstage.h
> +++ b/arch/riscv/include/asm/kvm_gstage.h
> @@ -29,16 +29,22 @@ struct kvm_gstage_mapping {
> #define kvm_riscv_gstage_index_bits 10
> #endif
>
> -extern unsigned long kvm_riscv_gstage_mode;
> -extern unsigned long kvm_riscv_gstage_pgd_levels;
> +extern unsigned long kvm_riscv_gstage_max_pgd_levels;
>
> #define kvm_riscv_gstage_pgd_xbits 2
> #define kvm_riscv_gstage_pgd_size (1UL << (HGATP_PAGE_SHIFT + kvm_riscv_gstage_pgd_xbits))
> -#define kvm_riscv_gstage_gpa_bits (HGATP_PAGE_SHIFT + \
> - (kvm_riscv_gstage_pgd_levels * \
> - kvm_riscv_gstage_index_bits) + \
> - kvm_riscv_gstage_pgd_xbits)
> -#define kvm_riscv_gstage_gpa_size ((gpa_t)(1ULL << kvm_riscv_gstage_gpa_bits))
> +
> +static inline unsigned long kvm_riscv_gstage_gpa_bits(unsigned long pgd_levels)
> +{
> + return (HGATP_PAGE_SHIFT +
> + pgd_levels * kvm_riscv_gstage_index_bits +
> + kvm_riscv_gstage_pgd_xbits);
> +}
> +
> +static inline gpa_t kvm_riscv_gstage_gpa_size(unsigned long pgd_levels)
> +{
> + return BIT_ULL(kvm_riscv_gstage_gpa_bits(pgd_levels));
> +}
>
> bool kvm_riscv_gstage_get_leaf(struct kvm_gstage *gstage, gpa_t addr,
> pte_t **ptepp, u32 *ptep_level);
> @@ -69,4 +75,21 @@ void kvm_riscv_gstage_wp_range(struct kvm_gstage *gstage, gpa_t start, gpa_t end
>
> void kvm_riscv_gstage_mode_detect(void);
>
> +static inline unsigned long kvm_riscv_gstage_mode(unsigned long pgd_levels)
> +{
> + switch (pgd_levels) {
> + case 2:
> + return HGATP_MODE_SV32X4;
> + case 3:
> + return HGATP_MODE_SV39X4;
> + case 4:
> + return HGATP_MODE_SV48X4;
> + case 5:
> + return HGATP_MODE_SV57X4;
> + default:
> + WARN_ON_ONCE(1);
> + return HGATP_MODE_OFF;
> + }
> +}
> +
> #endif
> diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
> index 24585304c02b..478f699e9dec 100644
> --- a/arch/riscv/include/asm/kvm_host.h
> +++ b/arch/riscv/include/asm/kvm_host.h
> @@ -94,6 +94,7 @@ struct kvm_arch {
> /* G-stage page table */
> pgd_t *pgd;
> phys_addr_t pgd_phys;
> + unsigned long pgd_levels;
>
> /* Guest Timer */
> struct kvm_guest_timer timer;
> diff --git a/arch/riscv/kvm/gstage.c b/arch/riscv/kvm/gstage.c
> index b67d60d722c2..4beb9322fe76 100644
> --- a/arch/riscv/kvm/gstage.c
> +++ b/arch/riscv/kvm/gstage.c
> @@ -12,22 +12,21 @@
> #include <asm/kvm_gstage.h>
>
> #ifdef CONFIG_64BIT
> -unsigned long kvm_riscv_gstage_mode __ro_after_init = HGATP_MODE_SV39X4;
> -unsigned long kvm_riscv_gstage_pgd_levels __ro_after_init = 3;
> +unsigned long kvm_riscv_gstage_max_pgd_levels __ro_after_init = 3;
> #else
> -unsigned long kvm_riscv_gstage_mode __ro_after_init = HGATP_MODE_SV32X4;
> -unsigned long kvm_riscv_gstage_pgd_levels __ro_after_init = 2;
> +unsigned long kvm_riscv_gstage_max_pgd_levels __ro_after_init = 2;
> #endif
>
> #define gstage_pte_leaf(__ptep) \
> (pte_val(*(__ptep)) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC))
>
> -static inline unsigned long gstage_pte_index(gpa_t addr, u32 level)
> +static inline unsigned long gstage_pte_index(struct kvm_gstage *gstage,
> + gpa_t addr, u32 level)
> {
> unsigned long mask;
> unsigned long shift = HGATP_PAGE_SHIFT + (kvm_riscv_gstage_index_bits * level);
>
> - if (level == (kvm_riscv_gstage_pgd_levels - 1))
> + if (level == gstage->kvm->arch.pgd_levels - 1)
> mask = (PTRS_PER_PTE * (1UL << kvm_riscv_gstage_pgd_xbits)) - 1;
> else
> mask = PTRS_PER_PTE - 1;
> @@ -40,12 +39,13 @@ static inline unsigned long gstage_pte_page_vaddr(pte_t pte)
> return (unsigned long)pfn_to_virt(__page_val_to_pfn(pte_val(pte)));
> }
>
> -static int gstage_page_size_to_level(unsigned long page_size, u32 *out_level)
> +static int gstage_page_size_to_level(struct kvm_gstage *gstage, unsigned long page_size,
> + u32 *out_level)
> {
> u32 i;
> unsigned long psz = 1UL << 12;
>
> - for (i = 0; i < kvm_riscv_gstage_pgd_levels; i++) {
> + for (i = 0; i < gstage->kvm->arch.pgd_levels; i++) {
> if (page_size == (psz << (i * kvm_riscv_gstage_index_bits))) {
> *out_level = i;
> return 0;
> @@ -55,21 +55,23 @@ static int gstage_page_size_to_level(unsigned long page_size, u32 *out_level)
> return -EINVAL;
> }
>
> -static int gstage_level_to_page_order(u32 level, unsigned long *out_pgorder)
> +static int gstage_level_to_page_order(struct kvm_gstage *gstage, u32 level,
> + unsigned long *out_pgorder)
> {
> - if (kvm_riscv_gstage_pgd_levels < level)
> + if (gstage->kvm->arch.pgd_levels < level)
> return -EINVAL;
>
> *out_pgorder = 12 + (level * kvm_riscv_gstage_index_bits);
> return 0;
> }
>
> -static int gstage_level_to_page_size(u32 level, unsigned long *out_pgsize)
> +static int gstage_level_to_page_size(struct kvm_gstage *gstage, u32 level,
> + unsigned long *out_pgsize)
> {
> int rc;
> unsigned long page_order = PAGE_SHIFT;
>
> - rc = gstage_level_to_page_order(level, &page_order);
> + rc = gstage_level_to_page_order(gstage, level, &page_order);
> if (rc)
> return rc;
>
> @@ -81,11 +83,11 @@ bool kvm_riscv_gstage_get_leaf(struct kvm_gstage *gstage, gpa_t addr,
> pte_t **ptepp, u32 *ptep_level)
> {
> pte_t *ptep;
> - u32 current_level = kvm_riscv_gstage_pgd_levels - 1;
> + u32 current_level = gstage->kvm->arch.pgd_levels - 1;
>
> *ptep_level = current_level;
> ptep = (pte_t *)gstage->pgd;
> - ptep = &ptep[gstage_pte_index(addr, current_level)];
> + ptep = &ptep[gstage_pte_index(gstage, addr, current_level)];
> while (ptep && pte_val(ptep_get(ptep))) {
> if (gstage_pte_leaf(ptep)) {
> *ptep_level = current_level;
> @@ -97,7 +99,7 @@ bool kvm_riscv_gstage_get_leaf(struct kvm_gstage *gstage, gpa_t addr,
> current_level--;
> *ptep_level = current_level;
> ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep));
> - ptep = &ptep[gstage_pte_index(addr, current_level)];
> + ptep = &ptep[gstage_pte_index(gstage, addr, current_level)];
> } else {
> ptep = NULL;
> }
> @@ -110,7 +112,7 @@ static void gstage_tlb_flush(struct kvm_gstage *gstage, u32 level, gpa_t addr)
> {
> unsigned long order = PAGE_SHIFT;
>
> - if (gstage_level_to_page_order(level, &order))
> + if (gstage_level_to_page_order(gstage, level, &order))
> return;
> addr &= ~(BIT(order) - 1);
>
> @@ -125,9 +127,9 @@ int kvm_riscv_gstage_set_pte(struct kvm_gstage *gstage,
> struct kvm_mmu_memory_cache *pcache,
> const struct kvm_gstage_mapping *map)
> {
> - u32 current_level = kvm_riscv_gstage_pgd_levels - 1;
> + u32 current_level = gstage->kvm->arch.pgd_levels - 1;
> pte_t *next_ptep = (pte_t *)gstage->pgd;
> - pte_t *ptep = &next_ptep[gstage_pte_index(map->addr, current_level)];
> + pte_t *ptep = &next_ptep[gstage_pte_index(gstage, map->addr, current_level)];
>
> if (current_level < map->level)
> return -EINVAL;
> @@ -151,7 +153,7 @@ int kvm_riscv_gstage_set_pte(struct kvm_gstage *gstage,
> }
>
> current_level--;
> - ptep = &next_ptep[gstage_pte_index(map->addr, current_level)];
> + ptep = &next_ptep[gstage_pte_index(gstage, map->addr, current_level)];
> }
>
> if (pte_val(*ptep) != pte_val(map->pte)) {
> @@ -175,7 +177,7 @@ int kvm_riscv_gstage_map_page(struct kvm_gstage *gstage,
> out_map->addr = gpa;
> out_map->level = 0;
>
> - ret = gstage_page_size_to_level(page_size, &out_map->level);
> + ret = gstage_page_size_to_level(gstage, page_size, &out_map->level);
> if (ret)
> return ret;
>
> @@ -217,7 +219,7 @@ void kvm_riscv_gstage_op_pte(struct kvm_gstage *gstage, gpa_t addr,
> u32 next_ptep_level;
> unsigned long next_page_size, page_size;
>
> - ret = gstage_level_to_page_size(ptep_level, &page_size);
> + ret = gstage_level_to_page_size(gstage, ptep_level, &page_size);
> if (ret)
> return;
>
> @@ -229,7 +231,7 @@ void kvm_riscv_gstage_op_pte(struct kvm_gstage *gstage, gpa_t addr,
> if (ptep_level && !gstage_pte_leaf(ptep)) {
> next_ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep));
> next_ptep_level = ptep_level - 1;
> - ret = gstage_level_to_page_size(next_ptep_level, &next_page_size);
> + ret = gstage_level_to_page_size(gstage, next_ptep_level, &next_page_size);
> if (ret)
> return;
>
> @@ -263,7 +265,7 @@ void kvm_riscv_gstage_unmap_range(struct kvm_gstage *gstage,
>
> while (addr < end) {
> found_leaf = kvm_riscv_gstage_get_leaf(gstage, addr, &ptep, &ptep_level);
> - ret = gstage_level_to_page_size(ptep_level, &page_size);
> + ret = gstage_level_to_page_size(gstage, ptep_level, &page_size);
> if (ret)
> break;
>
> @@ -297,7 +299,7 @@ void kvm_riscv_gstage_wp_range(struct kvm_gstage *gstage, gpa_t start, gpa_t end
>
> while (addr < end) {
> found_leaf = kvm_riscv_gstage_get_leaf(gstage, addr, &ptep, &ptep_level);
> - ret = gstage_level_to_page_size(ptep_level, &page_size);
> + ret = gstage_level_to_page_size(gstage, ptep_level, &page_size);
> if (ret)
> break;
>
> @@ -319,39 +321,34 @@ void __init kvm_riscv_gstage_mode_detect(void)
> /* Try Sv57x4 G-stage mode */
> csr_write(CSR_HGATP, HGATP_MODE_SV57X4 << HGATP_MODE_SHIFT);
> if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV57X4) {
> - kvm_riscv_gstage_mode = HGATP_MODE_SV57X4;
> - kvm_riscv_gstage_pgd_levels = 5;
> + kvm_riscv_gstage_max_pgd_levels = 5;
> goto done;
> }
>
> /* Try Sv48x4 G-stage mode */
> csr_write(CSR_HGATP, HGATP_MODE_SV48X4 << HGATP_MODE_SHIFT);
> if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV48X4) {
> - kvm_riscv_gstage_mode = HGATP_MODE_SV48X4;
> - kvm_riscv_gstage_pgd_levels = 4;
> + kvm_riscv_gstage_max_pgd_levels = 4;
> goto done;
> }
>
> /* Try Sv39x4 G-stage mode */
> csr_write(CSR_HGATP, HGATP_MODE_SV39X4 << HGATP_MODE_SHIFT);
> if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV39X4) {
> - kvm_riscv_gstage_mode = HGATP_MODE_SV39X4;
> - kvm_riscv_gstage_pgd_levels = 3;
> + kvm_riscv_gstage_max_pgd_levels = 3;
> goto done;
> }
> #else /* CONFIG_32BIT */
> /* Try Sv32x4 G-stage mode */
> csr_write(CSR_HGATP, HGATP_MODE_SV32X4 << HGATP_MODE_SHIFT);
> if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV32X4) {
> - kvm_riscv_gstage_mode = HGATP_MODE_SV32X4;
> - kvm_riscv_gstage_pgd_levels = 2;
> + kvm_riscv_gstage_max_pgd_levels = 2;
> goto done;
> }
> #endif
>
> /* KVM depends on !HGATP_MODE_OFF */
> - kvm_riscv_gstage_mode = HGATP_MODE_OFF;
> - kvm_riscv_gstage_pgd_levels = 0;
> + kvm_riscv_gstage_max_pgd_levels = 0;
>
> done:
> csr_write(CSR_HGATP, 0);
> diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c
> index 0f3fe3986fc0..90ee0a032b9a 100644
> --- a/arch/riscv/kvm/main.c
> +++ b/arch/riscv/kvm/main.c
> @@ -105,17 +105,17 @@ static int __init riscv_kvm_init(void)
> return rc;
>
> kvm_riscv_gstage_mode_detect();
> - switch (kvm_riscv_gstage_mode) {
> - case HGATP_MODE_SV32X4:
> + switch (kvm_riscv_gstage_max_pgd_levels) {
> + case 2:
> str = "Sv32x4";
> break;
> - case HGATP_MODE_SV39X4:
> + case 3:
> str = "Sv39x4";
> break;
> - case HGATP_MODE_SV48X4:
> + case 4:
> str = "Sv48x4";
> break;
> - case HGATP_MODE_SV57X4:
> + case 5:
> str = "Sv57x4";
> break;
> default:
> @@ -164,7 +164,7 @@ static int __init riscv_kvm_init(void)
> (rc) ? slist : "no features");
> }
>
> - kvm_info("using %s G-stage page table format\n", str);
> + kvm_info("highest G-stage page table mode is %s\n", str);
>
> kvm_info("VMID %ld bits available\n", kvm_riscv_gstage_vmid_bits());
>
> diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
> index 088d33ba90ed..fbcdd75cb9af 100644
> --- a/arch/riscv/kvm/mmu.c
> +++ b/arch/riscv/kvm/mmu.c
> @@ -67,7 +67,7 @@ int kvm_riscv_mmu_ioremap(struct kvm *kvm, gpa_t gpa, phys_addr_t hpa,
> if (!writable)
> map.pte = pte_wrprotect(map.pte);
>
> - ret = kvm_mmu_topup_memory_cache(&pcache, kvm_riscv_gstage_pgd_levels);
> + ret = kvm_mmu_topup_memory_cache(&pcache, kvm->arch.pgd_levels);
> if (ret)
> goto out;
>
> @@ -186,7 +186,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
> * space addressable by the KVM guest GPA space.
> */
> if ((new->base_gfn + new->npages) >=
> - (kvm_riscv_gstage_gpa_size >> PAGE_SHIFT))
> + kvm_riscv_gstage_gpa_size(kvm->arch.pgd_levels) >> PAGE_SHIFT)
> return -EFAULT;
>
> hva = new->userspace_addr;
> @@ -472,7 +472,7 @@ int kvm_riscv_mmu_map(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
> memset(out_map, 0, sizeof(*out_map));
>
> /* We need minimum second+third level pages */
> - ret = kvm_mmu_topup_memory_cache(pcache, kvm_riscv_gstage_pgd_levels);
> + ret = kvm_mmu_topup_memory_cache(pcache, kvm->arch.pgd_levels);
> if (ret) {
> kvm_err("Failed to topup G-stage cache\n");
> return ret;
> @@ -575,6 +575,7 @@ int kvm_riscv_mmu_alloc_pgd(struct kvm *kvm)
> return -ENOMEM;
> kvm->arch.pgd = page_to_virt(pgd_page);
> kvm->arch.pgd_phys = page_to_phys(pgd_page);
> + kvm->arch.pgd_levels = kvm_riscv_gstage_max_pgd_levels;
>
> return 0;
> }
> @@ -590,10 +591,12 @@ void kvm_riscv_mmu_free_pgd(struct kvm *kvm)
> gstage.flags = 0;
> gstage.vmid = READ_ONCE(kvm->arch.vmid.vmid);
> gstage.pgd = kvm->arch.pgd;
> - kvm_riscv_gstage_unmap_range(&gstage, 0UL, kvm_riscv_gstage_gpa_size, false);
> + kvm_riscv_gstage_unmap_range(&gstage, 0UL,
> + kvm_riscv_gstage_gpa_size(kvm->arch.pgd_levels), false);
> pgd = READ_ONCE(kvm->arch.pgd);
> kvm->arch.pgd = NULL;
> kvm->arch.pgd_phys = 0;
> + kvm->arch.pgd_levels = 0;
> }
> spin_unlock(&kvm->mmu_lock);
>
> @@ -603,11 +606,12 @@ void kvm_riscv_mmu_free_pgd(struct kvm *kvm)
>
> void kvm_riscv_mmu_update_hgatp(struct kvm_vcpu *vcpu)
> {
> - unsigned long hgatp = kvm_riscv_gstage_mode << HGATP_MODE_SHIFT;
> - struct kvm_arch *k = &vcpu->kvm->arch;
> + struct kvm_arch *ka = &vcpu->kvm->arch;
> + unsigned long hgatp = kvm_riscv_gstage_mode(ka->pgd_levels)
> + << HGATP_MODE_SHIFT;
>
> - hgatp |= (READ_ONCE(k->vmid.vmid) << HGATP_VMID_SHIFT) & HGATP_VMID;
> - hgatp |= (k->pgd_phys >> PAGE_SHIFT) & HGATP_PPN;
> + hgatp |= (READ_ONCE(ka->vmid.vmid) << HGATP_VMID_SHIFT) & HGATP_VMID;
> + hgatp |= (ka->pgd_phys >> PAGE_SHIFT) & HGATP_PPN;
>
> ncsr_write(CSR_HGATP, hgatp);
>
> diff --git a/arch/riscv/kvm/vm.c b/arch/riscv/kvm/vm.c
> index 13c63ae1a78b..4d82a886102c 100644
> --- a/arch/riscv/kvm/vm.c
> +++ b/arch/riscv/kvm/vm.c
> @@ -199,7 +199,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
> r = KVM_USER_MEM_SLOTS;
> break;
> case KVM_CAP_VM_GPA_BITS:
> - r = kvm_riscv_gstage_gpa_bits;
> + r = kvm_riscv_gstage_gpa_bits(kvm->arch.pgd_levels);
> break;
> default:
> r = 0;
> diff --git a/arch/riscv/kvm/vmid.c b/arch/riscv/kvm/vmid.c
> index cf34d448289d..c15bdb1dd8be 100644
> --- a/arch/riscv/kvm/vmid.c
> +++ b/arch/riscv/kvm/vmid.c
> @@ -26,7 +26,8 @@ static DEFINE_SPINLOCK(vmid_lock);
> void __init kvm_riscv_gstage_vmid_detect(void)
> {
> /* Figure-out number of VMID bits in HW */
> - csr_write(CSR_HGATP, (kvm_riscv_gstage_mode << HGATP_MODE_SHIFT) | HGATP_VMID);
> + csr_write(CSR_HGATP, (kvm_riscv_gstage_mode(kvm_riscv_gstage_max_pgd_levels) <<
> + HGATP_MODE_SHIFT) | HGATP_VMID);
> vmid_bits = csr_read(CSR_HGATP);
> vmid_bits = (vmid_bits & HGATP_VMID) >> HGATP_VMID_SHIFT;
> vmid_bits = fls_long(vmid_bits);
> --
> 2.50.1
>
Reviewed-by: Guo Ren <guoren@kernel.org>
--
Best Regards
Guo Ren
© 2016 - 2026 Red Hat, Inc.