For cpuid, this means putting hooks into the vmexit handler to call it instead
of the hvm one.
For IO, this now means putting a hook into the emulation code to call the PV
guest_io_{read,write} functions.
NB at this point this won't do the full "copy and execute on the stack
with full GPRs" work-around; this may need to be sorted out for dom0 to allow
these instructions to happen in guest context.
Signed-off-by: George Dunlap <george.dunlap@xxxxxxxxxxxxx>
Signed-off-by: Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>
---
v14-hvmio:
- Use HVM path to emulate IO, calling into PV just for the final IO
- Don't support forced invalid ops any more (so we can avoid PV emulation
altogether)
v13:
- Remove unnecessary privilege check in PIO path, update related comment
- Move ? and : to end of line rather than beginning, as requested
CC: Jan Beulich <jbeulich@xxxxxxxx>
CC: Tim Deegan <tim@xxxxxxx>
CC: Keir Fraser <keir@xxxxxxx>
---
xen/arch/x86/hvm/emulate.c | 75 ++++++++++++++++++++++++++++++++++-----
xen/arch/x86/hvm/vmx/vmx.c | 3 +-
xen/arch/x86/traps.c | 6 ++--
xen/include/asm-x86/processor.h | 2 ++
xen/include/asm-x86/traps.h | 8 +++++
5 files changed, 81 insertions(+), 13 deletions(-)
diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c
index a41eaa1..0d767c2 100644
--- a/xen/arch/x86/hvm/emulate.c
+++ b/xen/arch/x86/hvm/emulate.c
@@ -16,14 +16,14 @@
#include <xen/paging.h>
#include <xen/trace.h>
#include <asm/event.h>
+#include <asm/traps.h>
#include <asm/xstate.h>
#include <asm/hvm/emulate.h>
#include <asm/hvm/hvm.h>
#include <asm/hvm/trace.h>
#include <asm/hvm/support.h>
-static void hvmtrace_io_assist(int is_mmio, ioreq_t *p)
-{
+static void trace_io_assist(int is_mmio, int dir, int data_valid, paddr_t
addr, unsigned int data) {
unsigned int size, event;
unsigned char buffer[12];
@@ -31,22 +31,28 @@ static void hvmtrace_io_assist(int is_mmio, ioreq_t *p)
return;
if ( is_mmio )
- event = p->dir ? TRC_HVM_IOMEM_READ : TRC_HVM_IOMEM_WRITE;
+ event = dir ? TRC_HVM_IOMEM_READ : TRC_HVM_IOMEM_WRITE;
else
- event = p->dir ? TRC_HVM_IOPORT_READ : TRC_HVM_IOPORT_WRITE;
+ event = dir ? TRC_HVM_IOPORT_READ : TRC_HVM_IOPORT_WRITE;
- *(uint64_t *)buffer = p->addr;
- size = (p->addr != (u32)p->addr) ? 8 : 4;
+ *(uint64_t *)buffer = addr;
+ size = (addr != (u32)addr) ? 8 : 4;
if ( size == 8 )
event |= TRC_64_FLAG;
- if ( !p->data_is_ptr )
+ if ( data_valid )
{
- *(uint32_t *)&buffer[size] = p->data;
+ *(uint32_t *)&buffer[size] = data;
size += 4;
}
trace_var(event, 0/*!cycles*/, size, buffer);
+
+}
+
+static void hvmtrace_io_assist(int is_mmio, ioreq_t *p)
+{
+ trace_io_assist(is_mmio, p->dir, !p->data_is_ptr, p->addr, p->data);
}
static int hvmemul_do_io(
@@ -140,6 +146,9 @@ static int hvmemul_do_io(
}
}
+ if ( is_pvh_vcpu(curr) )
+ ASSERT(vio->io_state == HVMIO_none);
+
switch ( vio->io_state )
{
case HVMIO_none:
@@ -284,11 +293,59 @@ static int hvmemul_do_io(
return X86EMUL_OKAY;
}
+static int pvhemul_do_pio(
+ unsigned long port, int size, paddr_t ram_gpa, int dir, void *p_data)
+{
+ paddr_t value = ram_gpa;
+ struct vcpu *curr = current;
+ struct cpu_user_regs *regs = guest_cpu_user_regs();
+
+ /*
+ * Weird-sized accesses have undefined behaviour: we discard writes
+ * and read all-ones.
+ */
+ if ( unlikely((size > sizeof(long)) || (size & (size - 1))) )
+ {
+ gdprintk(XENLOG_WARNING, "bad mmio size %d\n", size);
+ ASSERT(p_data != NULL); /* cannot happen with a REP prefix */
+ if ( dir == IOREQ_READ )
+ memset(p_data, ~0, size);
+ return X86EMUL_UNHANDLEABLE;
+ }
+
+ if ( dir == IOREQ_WRITE ) {
+ if ( (p_data != NULL) )
+ {
+ memcpy(&value, p_data, size);
+ p_data = NULL;
+ }
+
+ if ( dir == IOREQ_WRITE )
+ trace_io_assist(0, dir, 1, port, value);
+
+ guest_io_write(port, size, value, curr, regs);
+ }
+ else
+ {
+ value = guest_io_read(port, size, curr, regs);
+ trace_io_assist(0, dir, 1, port, value);
+ if ( (p_data != NULL) )
+ memcpy(p_data, &value, size);
+ memcpy(®s->eax, &value, size);
+ }
+
+ return X86EMUL_OKAY;
+}
+
+
int hvmemul_do_pio(
unsigned long port, unsigned long *reps, int size,
paddr_t ram_gpa, int dir, int df, void *p_data)
{
- return hvmemul_do_io(0, port, reps, size, ram_gpa, dir, df, p_data);
+ return is_hvm_vcpu(current) ?
+ hvmemul_do_io(0, port, reps, size, ram_gpa, dir, df, p_data) :
+ pvhemul_do_pio(port, size, ram_gpa, dir, p_data);
+
}
static int hvmemul_do_mmio(
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 94e9e21..5d1e367 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -56,6 +56,7 @@
#include <asm/apic.h>
#include <asm/hvm/nestedhvm.h>
#include <asm/event.h>
+#include <asm/traps.h>
enum handler_return { HNDL_done, HNDL_unhandled, HNDL_exception_raised };
@@ -2694,8 +2695,8 @@ void vmx_vmexit_handler(struct cpu_user_regs *regs)
break;
}
case EXIT_REASON_CPUID:
+ is_pvh_vcpu(v) ? pv_cpuid(regs) : vmx_do_cpuid(regs);
update_guest_eip(); /* Safe: CPUID */
- vmx_do_cpuid(regs);
break;
case EXIT_REASON_HLT:
update_guest_eip(); /* Safe: HLT */
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index edb7a6a..6c278bc 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -729,7 +729,7 @@ int cpuid_hypervisor_leaves( uint32_t idx, uint32_t sub_idx,
return 1;
}
-static void pv_cpuid(struct cpu_user_regs *regs)
+void pv_cpuid(struct cpu_user_regs *regs)
{
uint32_t a, b, c, d;
@@ -1681,7 +1681,7 @@ static int pci_cfg_ok(struct domain *d, int write, int size)
return 1;
}
-static uint32_t guest_io_read(
+uint32_t guest_io_read(
unsigned int port, unsigned int bytes,
struct vcpu *v, struct cpu_user_regs *regs)
{
@@ -1748,7 +1748,7 @@ static uint32_t guest_io_read(
return data;
}
-static void guest_io_write(
+void guest_io_write(
unsigned int port, unsigned int bytes, uint32_t data,
struct vcpu *v, struct cpu_user_regs *regs)
{
diff --git a/xen/include/asm-x86/processor.h b/xen/include/asm-x86/processor.h
index 893afa3..551036d 100644
--- a/xen/include/asm-x86/processor.h
+++ b/xen/include/asm-x86/processor.h
@@ -567,6 +567,8 @@ void microcode_set_module(unsigned int);
int microcode_update(XEN_GUEST_HANDLE_PARAM(const_void), unsigned long len);
int microcode_resume_cpu(int cpu);
+void pv_cpuid(struct cpu_user_regs *regs);
+
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_X86_PROCESSOR_H */
diff --git a/xen/include/asm-x86/traps.h b/xen/include/asm-x86/traps.h
index 82cbcee..a26b318 100644
--- a/xen/include/asm-x86/traps.h
+++ b/xen/include/asm-x86/traps.h
@@ -49,4 +49,12 @@ extern int guest_has_trap_callback(struct domain *d,
uint16_t vcpuid,
extern int send_guest_trap(struct domain *d, uint16_t vcpuid,
unsigned int trap_nr);
+uint32_t guest_io_read(
+ unsigned int port, unsigned int bytes,
+ struct vcpu *v, struct cpu_user_regs *regs);
+void guest_io_write(
+ unsigned int port, unsigned int bytes, uint32_t data,
+ struct vcpu *v, struct cpu_user_regs *regs);
+
+
#endif /* ASM_TRAP_H */
