github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-27 02:22:02 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

RISC-V: KVM: Widen G-stage fault address to gpa_t

Browse Source 
fault_addr in gstage_page_fault() and the fault_addr parameter of
kvm_riscv_vcpu_mmio_load/store() are unsigned long.  On RV32 with
Sv32x4, guest physical addresses are 34 bits, so a 32-bit unsigned
long truncates bits 32/33 at two points:

  - reconstruction: fault_addr = (trap->htval << 2) | ... is evaluated
    in 32-bit arithmetic, dropping bits 32/33 before widening;
  - the MMIO handler call: even with the local widened, the handler's
    unsigned long parameter narrows it back to 32 bits, aliasing
    accesses above 4 GB into the low 4 GB.

Widen fault_addr to gpa_t end to end: the local in gstage_page_fault(),
the (gpa_t) cast before the <<2 shift, and the fault_addr parameters of
kvm_riscv_vcpu_mmio_load/store().  The handlers' internal uses
(run->mmio.phys_addr is __u64, kvm_io_bus_read/write() take gpa_t) are
already 64-bit, so no further changes are needed.

Also in preparation for sharing a common struct kvm_page_fault across
architectures, where fault_addr is gpa_t.  No functional change on RV64.

Fixes: 9d05c1fee8 ("RISC-V: KVM: Implement stage2 page table programming")
Assisted-by: YuanSheng: deepseek-v4-pro
Co-developed-by: Quan Zhou <zhouquan@iscas.ac.cn>
Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn>
Signed-off-by: Bingyu Xian <shanbeeyoo@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260729120733.829457-4-shanbeeyoo@gmail.com
Signed-off-by: Anup Patel <anup@brainfault.org>
This commit is contained in:
Bingyu.Xian 2026-07-29 20:07:33 +08:00 committed by Anup Patel
parent ed2300fabb
commit 739dfb8b4b
3 changed files with 7 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/riscv/include/asm/kvm_vcpu_insn.h
View File

@ -38,10 +38,10 @@ int kvm_riscv_vcpu_virtual_insn(struct kvm_vcpu *vcpu, struct kvm_run *run,
struct kvm_cpu_trap *trap);
int kvm_riscv_vcpu_mmio_load(struct kvm_vcpu *vcpu, struct kvm_run *run,
unsigned long fault_addr,
gpa_t fault_addr,
unsigned long htinst);
int kvm_riscv_vcpu_mmio_store(struct kvm_vcpu *vcpu, struct kvm_run *run,
unsigned long fault_addr,
gpa_t fault_addr,
unsigned long htinst);
int kvm_riscv_vcpu_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run);

5
arch/riscv/kvm/vcpu_exit.c
View File

@ -17,12 +17,13 @@ static int gstage_page_fault(struct kvm_vcpu *vcpu, struct kvm_run *run,
{
struct kvm_gstage_mapping host_map;
struct kvm_memory_slot *memslot;
unsigned long hva, fault_addr;
unsigned long hva;
gpa_t fault_addr;
bool writable;
gfn_t gfn;
int ret;
fault_addr = (trap->htval << 2) | (trap->stval & 0x3);
fault_addr = ((gpa_t)trap->htval << 2) | (trap->stval & 0x3);
gfn = fault_addr >> PAGE_SHIFT;
memslot = gfn_to_memslot(vcpu->kvm, gfn);
hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);

4
arch/riscv/kvm/vcpu_insn.c
View File

@ -371,7 +371,7 @@ int kvm_riscv_vcpu_virtual_insn(struct kvm_vcpu *vcpu, struct kvm_run *run,
* Returns < 0 to report failure and exit run-loop
*/
int kvm_riscv_vcpu_mmio_load(struct kvm_vcpu *vcpu, struct kvm_run *run,
unsigned long fault_addr,
gpa_t fault_addr,
unsigned long htinst)
{
u8 data_buf[8];
@ -494,7 +494,7 @@ int kvm_riscv_vcpu_mmio_load(struct kvm_vcpu *vcpu, struct kvm_run *run,
* Returns < 0 to report failure and exit run-loop
*/
int kvm_riscv_vcpu_mmio_store(struct kvm_vcpu *vcpu, struct kvm_run *run,
unsigned long fault_addr,
gpa_t fault_addr,
unsigned long htinst)
{
u8 data8;