Commit f035b44b authored by Anup Patel's avatar Anup Patel Committed by Anup Patel
Browse files

RISC-V: KVM: Introduce struct kvm_gstage_mapping 



Introduce struct kvm_gstage_mapping which represents a g-stage
mapping at a particular g-stage page table level. Also, update
the kvm_riscv_gstage_map() to return the g-stage mapping upon
success.

Signed-off-by: default avatarAnup Patel <apatel@ventanamicro.com>
Reviewed-by: default avatarAtish Patra <atishp@rivosinc.com>
Tested-by: default avatarAtish Patra <atishp@rivosinc.com>
Reviewed-by: default avatarNutty Liu <liujingqi@lanxincomputing.com>
Link: https://lore.kernel.org/r/20250618113532.471448-10-apatel@ventanamicro.com


Signed-off-by: default avatarAnup Patel <anup@brainfault.org>
parent 4ecbd3eb

arch/riscv/include/asm/kvm_mmu.h

+8 −1
Original line number Diff line number Diff line
@@ -8,6 +8,12 @@ 


#include <linux/kvm_types.h>



struct kvm_gstage_mapping {

	gpa_t addr;

	pte_t pte;

	u32 level;

};



int kvm_riscv_gstage_ioremap(struct kvm *kvm, gpa_t gpa,

			     phys_addr_t hpa, unsigned long size,

			     bool writable, bool in_atomic);
@@ -15,7 +21,8 @@ void kvm_riscv_gstage_iounmap(struct kvm *kvm, gpa_t gpa, 
			      unsigned long size);

int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu,

			 struct kvm_memory_slot *memslot,

			 gpa_t gpa, unsigned long hva, bool is_write);

			 gpa_t gpa, unsigned long hva, bool is_write,

			 struct kvm_gstage_mapping *out_map);

int kvm_riscv_gstage_alloc_pgd(struct kvm *kvm);

void kvm_riscv_gstage_free_pgd(struct kvm *kvm);

void kvm_riscv_gstage_update_hgatp(struct kvm_vcpu *vcpu);

arch/riscv/kvm/mmu.c

+33 −25
Original line number Diff line number Diff line
@@ -135,18 +135,18 @@ static void gstage_remote_tlb_flush(struct kvm *kvm, u32 level, gpa_t addr) 
	kvm_riscv_hfence_gvma_vmid_gpa(kvm, -1UL, 0, addr, BIT(order), order);

}



static int gstage_set_pte(struct kvm *kvm, u32 level,

static int gstage_set_pte(struct kvm *kvm,

			  struct kvm_mmu_memory_cache *pcache,

			   gpa_t addr, const pte_t *new_pte)

			  const struct kvm_gstage_mapping *map)

{

	u32 current_level = gstage_pgd_levels - 1;

	pte_t *next_ptep = (pte_t *)kvm->arch.pgd;

	pte_t *ptep = &next_ptep[gstage_pte_index(addr, current_level)];

	pte_t *ptep = &next_ptep[gstage_pte_index(map->addr, current_level)];



	if (current_level < level)

	if (current_level < map->level)

		return -EINVAL;



	while (current_level != level) {

	while (current_level != map->level) {

		if (gstage_pte_leaf(ptep))

			return -EEXIST;
@@ -165,13 +165,13 @@ static int gstage_set_pte(struct kvm *kvm, u32 level, 
		}



		current_level--;

		ptep = &next_ptep[gstage_pte_index(addr, current_level)];

		ptep = &next_ptep[gstage_pte_index(map->addr, current_level)];

	}



	if (pte_val(*ptep) != pte_val(*new_pte)) {

		set_pte(ptep, *new_pte);

	if (pte_val(*ptep) != pte_val(map->pte)) {

		set_pte(ptep, map->pte);

		if (gstage_pte_leaf(ptep))

			gstage_remote_tlb_flush(kvm, current_level, addr);

			gstage_remote_tlb_flush(kvm, current_level, map->addr);

	}



	return 0;
@@ -181,14 +181,16 @@ static int gstage_map_page(struct kvm *kvm, 
			   struct kvm_mmu_memory_cache *pcache,

			   gpa_t gpa, phys_addr_t hpa,

			   unsigned long page_size,

			   bool page_rdonly, bool page_exec)

			   bool page_rdonly, bool page_exec,

			   struct kvm_gstage_mapping *out_map)

{

	int ret;

	u32 level = 0;

	pte_t new_pte;

	pgprot_t prot;

	int ret;



	ret = gstage_page_size_to_level(page_size, &level);

	out_map->addr = gpa;

	out_map->level = 0;



	ret = gstage_page_size_to_level(page_size, &out_map->level);

	if (ret)

		return ret;
@@ -216,10 +218,10 @@ static int gstage_map_page(struct kvm *kvm, 
		else

			prot = PAGE_WRITE;

	}

	new_pte = pfn_pte(PFN_DOWN(hpa), prot);

	new_pte = pte_mkdirty(new_pte);

	out_map->pte = pfn_pte(PFN_DOWN(hpa), prot);

	out_map->pte = pte_mkdirty(out_map->pte);



	return gstage_set_pte(kvm, level, pcache, gpa, &new_pte);

	return gstage_set_pte(kvm, pcache, out_map);

}



enum gstage_op {
@@ -352,7 +354,6 @@ int kvm_riscv_gstage_ioremap(struct kvm *kvm, gpa_t gpa, 
			     phys_addr_t hpa, unsigned long size,

			     bool writable, bool in_atomic)

{

	pte_t pte;

	int ret = 0;

	unsigned long pfn;

	phys_addr_t addr, end;
@@ -360,22 +361,25 @@ int kvm_riscv_gstage_ioremap(struct kvm *kvm, gpa_t gpa, 
		.gfp_custom = (in_atomic) ? GFP_ATOMIC | __GFP_ACCOUNT : 0,

		.gfp_zero = __GFP_ZERO,

	};

	struct kvm_gstage_mapping map;



	end = (gpa + size + PAGE_SIZE - 1) & PAGE_MASK;

	pfn = __phys_to_pfn(hpa);



	for (addr = gpa; addr < end; addr += PAGE_SIZE) {

		pte = pfn_pte(pfn, PAGE_KERNEL_IO);

		map.addr = addr;

		map.pte = pfn_pte(pfn, PAGE_KERNEL_IO);

		map.level = 0;



		if (!writable)

			pte = pte_wrprotect(pte);

			map.pte = pte_wrprotect(map.pte);



		ret = kvm_mmu_topup_memory_cache(&pcache, gstage_pgd_levels);

		if (ret)

			goto out;



		spin_lock(&kvm->mmu_lock);

		ret = gstage_set_pte(kvm, 0, &pcache, addr, &pte);

		ret = gstage_set_pte(kvm, &pcache, &map);

		spin_unlock(&kvm->mmu_lock);

		if (ret)

			goto out;
@@ -593,7 +597,8 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 


int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu,

			 struct kvm_memory_slot *memslot,

			 gpa_t gpa, unsigned long hva, bool is_write)

			 gpa_t gpa, unsigned long hva, bool is_write,

			 struct kvm_gstage_mapping *out_map)

{

	int ret;

	kvm_pfn_t hfn;
@@ -608,6 +613,9 @@ int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu, 
	unsigned long vma_pagesize, mmu_seq;

	struct page *page;



	/* Setup initial state of output mapping */

	memset(out_map, 0, sizeof(*out_map));



	/* We need minimum second+third level pages */

	ret = kvm_mmu_topup_memory_cache(pcache, gstage_pgd_levels);

	if (ret) {
@@ -677,10 +685,10 @@ int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu, 
	if (writable) {

		mark_page_dirty(kvm, gfn);

		ret = gstage_map_page(kvm, pcache, gpa, hfn << PAGE_SHIFT,

				      vma_pagesize, false, true);

				      vma_pagesize, false, true, out_map);

	} else {

		ret = gstage_map_page(kvm, pcache, gpa, hfn << PAGE_SHIFT,

				      vma_pagesize, true, true);

				      vma_pagesize, true, true, out_map);

	}



	if (ret)

arch/riscv/kvm/vcpu_exit.c

+2 −1
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
static int gstage_page_fault(struct kvm_vcpu *vcpu, struct kvm_run *run,

			     struct kvm_cpu_trap *trap)

{

	struct kvm_gstage_mapping host_map;

	struct kvm_memory_slot *memslot;

	unsigned long hva, fault_addr;

	bool writable;
@@ -43,7 +44,7 @@ static int gstage_page_fault(struct kvm_vcpu *vcpu, struct kvm_run *run, 
	}



	ret = kvm_riscv_gstage_map(vcpu, memslot, fault_addr, hva,

		(trap->scause == EXC_STORE_GUEST_PAGE_FAULT) ? true : false);

		(trap->scause == EXC_STORE_GUEST_PAGE_FAULT) ? true : false, &host_map);

	if (ret < 0)

		return ret;