| Message ID | 20241125195626.856992-19-jean-philippe@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | arm: Run Arm CCA VMs with KVM | expand |
Hi Jean, On 11/26/24 5:56 AM, Jean-Philippe Brucker wrote: > When RME is enabled, the upper GPA bit is used to distinguish protected > from unprotected addresses. Reserve it when setting up the guest memory > map. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> > --- > hw/arm/virt.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/hw/arm/virt.c b/hw/arm/virt.c > index 9836dfbdfb..eb94997914 100644 > --- a/hw/arm/virt.c > +++ b/hw/arm/virt.c > @@ -3035,14 +3035,24 @@ static int virt_kvm_type(MachineState *ms, const char *type_str) > VirtMachineState *vms = VIRT_MACHINE(ms); > int rme_vm_type = kvm_arm_rme_vm_type(ms); > int max_vm_pa_size, requested_pa_size; > + int rme_reserve_bit = 0; > bool fixed_ipa; > > - max_vm_pa_size = kvm_arm_get_max_vm_ipa_size(ms, &fixed_ipa); > + if (rme_vm_type) { > + /* > + * With RME, the upper GPA bit differentiates Realm from NS memory. > + * Reserve the upper bit to ensure that highmem devices will fit. > + */ > + rme_reserve_bit = 1; > + } > + > + max_vm_pa_size = kvm_arm_get_max_vm_ipa_size(ms, &fixed_ipa) - > + rme_reserve_bit; > For realm, @max_vm_pa_size is decreased by 1 ... > /* we freeze the memory map to compute the highest gpa */ > virt_set_memmap(vms, max_vm_pa_size); > > - requested_pa_size = 64 - clz64(vms->highest_gpa); > + requested_pa_size = 64 - clz64(vms->highest_gpa) + rme_reserve_bit; > ... For realm, @requested_pa_size is increased by 1, meaning there are two bits in the gap. > /* > * KVM requires the IPA size to be at least 32 bits. One bit instead of two bits seems the correct gap for the followup check? if (requested_pa_size > max_vm_pa_size) { error_report("-m and ,maxmem option values " "require an IPA range (%d bits) larger than " "the one supported by the host (%d bits)", requested_pa_size, max_vm_pa_size); return -1; } Thanks, Gavin
Hi Gavin, On Fri, Dec 13, 2024 at 10:03:08PM +1000, Gavin Shan wrote: > Hi Jean, > > On 11/26/24 5:56 AM, Jean-Philippe Brucker wrote: > > When RME is enabled, the upper GPA bit is used to distinguish protected > > from unprotected addresses. Reserve it when setting up the guest memory > > map. > > > > Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> > > --- > > hw/arm/virt.c | 14 ++++++++++++-- > > 1 file changed, 12 insertions(+), 2 deletions(-) > > > > diff --git a/hw/arm/virt.c b/hw/arm/virt.c > > index 9836dfbdfb..eb94997914 100644 > > --- a/hw/arm/virt.c > > +++ b/hw/arm/virt.c > > @@ -3035,14 +3035,24 @@ static int virt_kvm_type(MachineState *ms, const char *type_str) > > VirtMachineState *vms = VIRT_MACHINE(ms); > > int rme_vm_type = kvm_arm_rme_vm_type(ms); > > int max_vm_pa_size, requested_pa_size; > > + int rme_reserve_bit = 0; > > bool fixed_ipa; > > - max_vm_pa_size = kvm_arm_get_max_vm_ipa_size(ms, &fixed_ipa); > > + if (rme_vm_type) { > > + /* > > + * With RME, the upper GPA bit differentiates Realm from NS memory. > > + * Reserve the upper bit to ensure that highmem devices will fit. > > + */ > > + rme_reserve_bit = 1; > > + } > > + > > + max_vm_pa_size = kvm_arm_get_max_vm_ipa_size(ms, &fixed_ipa) - > > + rme_reserve_bit; > > For realm, @max_vm_pa_size is decreased by 1 ... > > > /* we freeze the memory map to compute the highest gpa */ > > virt_set_memmap(vms, max_vm_pa_size); > > - requested_pa_size = 64 - clz64(vms->highest_gpa); > > + requested_pa_size = 64 - clz64(vms->highest_gpa) + rme_reserve_bit; > > ... For realm, @requested_pa_size is increased by 1, meaning there are two bits in > the gap. I think it's a 1-bit gap: max_vm_pa_size is decreased by 1 for the purpose of memory map calculation, and here we increase by 1 what comes out of that calculation, for the KVM IPA size setting > > > /* > > * KVM requires the IPA size to be at least 32 bits. > > One bit instead of two bits seems the correct gap for the followup check? Yes this check seems wrong for realm, since (requested_pa_size == max_vm_pa_size + 1) should be valid in this case. I'll fix this. Thanks, Jean > > if (requested_pa_size > max_vm_pa_size) { > error_report("-m and ,maxmem option values " > "require an IPA range (%d bits) larger than " > "the one supported by the host (%d bits)", > requested_pa_size, max_vm_pa_size); > return -1; > } > > Thanks, > Gavin >
diff --git a/hw/arm/virt.c b/hw/arm/virt.c index 9836dfbdfb..eb94997914 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -3035,14 +3035,24 @@ static int virt_kvm_type(MachineState *ms, const char *type_str) VirtMachineState *vms = VIRT_MACHINE(ms); int rme_vm_type = kvm_arm_rme_vm_type(ms); int max_vm_pa_size, requested_pa_size; + int rme_reserve_bit = 0; bool fixed_ipa; - max_vm_pa_size = kvm_arm_get_max_vm_ipa_size(ms, &fixed_ipa); + if (rme_vm_type) { + /* + * With RME, the upper GPA bit differentiates Realm from NS memory. + * Reserve the upper bit to ensure that highmem devices will fit. + */ + rme_reserve_bit = 1; + } + + max_vm_pa_size = kvm_arm_get_max_vm_ipa_size(ms, &fixed_ipa) - + rme_reserve_bit; /* we freeze the memory map to compute the highest gpa */ virt_set_memmap(vms, max_vm_pa_size); - requested_pa_size = 64 - clz64(vms->highest_gpa); + requested_pa_size = 64 - clz64(vms->highest_gpa) + rme_reserve_bit; /* * KVM requires the IPA size to be at least 32 bits.
When RME is enabled, the upper GPA bit is used to distinguish protected from unprotected addresses. Reserve it when setting up the guest memory map. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> --- hw/arm/virt.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)